A light generating system generating red light

Abstract

: The invention provides a light generating system (1000) comprising a first light generating device (110), wherein the first light generating device (110) comprises a luminescent converter (2000) and one or more solid-state light sources (10,20,..), wherein - the one or more solid-state light sources (10,20,..) are configured to generate light source light (11,21,..) having a peak emission wavelength in a wavelength range of 280- 420 nm; - the luminescent converter (2000) is configured in a light receiving relationship with the one or more solid-state light sources (10,20,..); wherein the luminescent converter (2000) comprises a first luminescent material (210); wherein the first luminescent material (210) is a luminescent material of the type M'xM2-2xAX6 doped with tetravalent manganese, wherein M' comprises an alkaline earth cation, M comprises an monovalent cation, x is in the range of 0-1, A comprises a tetravalent cation, and wherein X comprises a monovalent anion, at least comprising fluorine; wherein the first luminescent material (210) is configured to convert at least part of the light source light (11,21,..) into first luminescent material light (211), wherein the first luminescent material light (211) has a first centroid wavelength (λc1) selected from the range of 610-650 nm and having a first full width at half maximum FWHM1 of ≤ 50 nm; and - the first light generating device (110) is configured to generate first device light (111) comprising the first luminescent material light (211); wherein the first device light (111) is red light; wherein the first light generating device (110) is configured such that (i) at least 95% of a spectral power distribution of the first device light (111) in a wavelength range of 380-780 nm is in the wavelength range of 590-780 nm, and at least 60% of a spectral power distribution of the first device light (111) in a wavelength range of 380-780 nm is provided by the first luminescent material light (211) and (ii) in a range of 0-5% of the spectral power distribution of the first device light (111) in the wavelength range of 380-780 nm is provided by the light source light (11,21,..).

Description

[0001] A light generating system generating red light

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a light generating system as well as to a lighting device comprising such light generating system.

[0004] BACKGROUND OF THE INVENTION

[0005] Light generating systems are known in the art. For instance, US20220389313A1 describes a white light emitting device comprising: an LED that generates excitation light of wavelength from 420 nm to 480 nm; and photoluminescence materials that generate light with a peak emission wavelength from 500 nm to 650 nm comprising a broadband phosphor, and a manganese-activated narrowband red fluoride phosphor with a peak emission wavelength from 628 nm to 640 nm and a full width at half maximum of less than 30 nm. The device generates white light with a selected color temperature from 2200K to 6500K, a General Color Rendering Index, CRI Ra, of at least 80, and a Duv (Delta u, v) from 0.0060 to 0.0170 for the selected color temperature and wherein the device has an LER (Luminous Efficacy of Radiation) of at least 320 Im / Wopt.

[0006] SUMMARY OF THE INVENTION

[0007] Conventional light generating systems (e.g. incandescent or fluorescent lamps) are rapidly being replaced by light emitting diode (LED) based lighting solutions. LED-based lighting solutions may generally comprise a blue-emitting light source and a luminescent converter, wherein the luminescent converter may comprise multiple types of phosphors, such as a yellow and a red phosphor, to produce especially white light with a suitable color temperature. Further, LED-based system may be used to produce colored light, such as for e.g. mood lighting. Colored light may be produced directly using a suitable LED material (direct-color LEDs or dc-LEDs), or may be based on the conversion of (especially) blue LED light by a luminescent converter (phosphor-converted LEDs or pc-LEDs). Pc-LEDs may in embodiments be more energy efficient than dc-LEDs, especially for the production of red light. To produce red light with a pc-LED, a luminescent converter comprising e.g. a high concentration of phosphor or a light filter may be used. However, prior art solutions may have problems to provide a reliable red color (over time or between different pc-LEDs), as phosphors may be unevenly distributed, or may degrade over time, allowing more or less blue light to be admixed with the luminescent material light. Upon admixing of more blue light into the red luminescent material light, the combined light may be perceived as purplish(-red) by a consumer. Hence, a color discrepancy may occur over time or between pc-LEDs, requiring pc-LEDs to be discarded during production or well before their expected lifespan has passed. This is undesired from an economic and durability standpoint. Hence, it is an aspect of the invention to provide an alternative light generating system, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0008] According to a first aspect, the invention provides a light generating system (“system”) comprising a first light generating device. In embodiments, the first light generating device comprises a luminescent converter. In embodiments, the first light generating device may comprise one or more solid-state light sources (“solid-state light sources”). In further embodiments, the one or more solid-state light sources may be configured to generate light source light having a peak emission wavelength in a wavelength range of 280-420 nm. Especially, the luminescent converter may be configured in a light receiving relationship with the one or more solid-state light sources. Further, in embodiments, the luminescent converter may comprise a first luminescent material. Especially, the first luminescent material may comprise a luminescent material of the type M’XM2-2XAX6 doped with tetravalent manganese. More especially, the first luminescent material is a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese. Furthermore, in embodiments, M’ may comprise an alkaline earth cation, M may comprise a monovalent cation, x may be in the range of 0-1, and A may comprise a tetravalent cation. Yet, in embodiments, X may comprise a monovalent anion, at least comprising fluorine. Especially, the first luminescent material may be configured to convert at least part of the light source light (received by the first luminescent material) into first luminescent material light. In embodiments, the first luminescent material light may have a first centroid wavelength (Ac 1 ) selected from the wavelength range of 610-650 nm, and may comprise one or more emission bands having a first full width half maximum (FWHM1) of at maximum 50 nm. Furthermore, in embodiments, the first light generating device may be configured to generate first device light comprising the first luminescent material light. Moreover, in embodiments, the first device light may be red light. In further embodiments, the first light generating device may be configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm may be provided by the first luminescent material light and (ii) in a range of 0-40% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm may be provided by the light source light. In yet other embodiments, the first light generating device may be configured such that (i) at least 50% of a spectral power distribution of the first device light in a wavelength range of 280-780 nm may be provided by the first luminescent material light and (ii) in a range of 0-50% of the spectral power distribution of the first device light in the wavelength range of 280-780 nm may be provided by the light source light. Hence, in specific embodiments the invention provides a light generating system comprising a first light generating device, wherein: (A) the first light generating device comprises a luminescent converter and one or more solid-state light sources; wherein the one or more solid-state light sources are configured to generate light source light having a peak emission wavelength in a wavelength range of 280-420 nm; (B) the luminescent converter is configured in a light receiving relationship with the one or more solid-state light sources; wherein the luminescent converter comprises a first luminescent material; wherein the first luminescent material is a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an monovalent cation, x is in the range of 0-1, A comprises a tetravalent cation, and wherein X comprises a monovalent anion, at least comprising fluorine; wherein the first luminescent material is configured to convert at least part of the light source light into first luminescent material light; wherein the first luminescent material light has a first centroid wavelength (kcl) selected from the wavelength range of 610-650 nm, and comprises one or more emission bands having a first full width half maximum (FWHM1) of at maximum 50 nm; and (C) the first light generating device is configured to generate first device light comprising the first luminescent material light; wherein the first device light is red light; wherein the first light generating device is configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm is provided by the first luminescent material light and (ii) in a range of 0-40% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm is provided by the light source light. Hence, in specific embodiments the invention provides a light generating system comprising a first light generating device and a luminescent converter, wherein: (A) the first light generating device comprises one or more light sources; wherein the one or more light sources are configured to generate light source light having spectral power in a wavelength range of 280-420 nm; (B) the luminescent converter is configured in a light receiving relationship with the one or more light sources; wherein the luminescent converter is configured in the transmissive mode; wherein the luminescent converter comprises a first luminescent material; wherein the first luminescent material comprises a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an monovalent cation, x is in the range of 0-1, A comprises a tetravalent cation, and wherein X comprises a monovalent anion, at least comprising fluorine; wherein the first luminescent material is configured to convert at least part of the light source light into first luminescent material light; and (C) the first light generating device is configured to generate first device light comprising the first luminescent material light; wherein the first device light is red light; wherein the first light generating device is configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm is provided by the first luminescent material light, and (ii) in a range of 0-40% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm is provided by the light source light.

[0009] With such light generating system, (first device) light may be provided that may essentially not change in color point over time, even though the luminescent material may degrade. Should with time the relative intensity of the light source light in the (first device) light increase, this may not be visible, as it may be invisible light (UV radiation), or may substantially not be visible (ultraviolet light), as the human eye may hardly perceive such light. Hence, the color point of the (first device) light may stay essentially the same over time. Hence, such a light generating system may provide red first device light. Especially, such a light generating system may facilitate that, even upon admixing part of the light source light into the first device light, the first device light may (essentially still) be perceived as red light by a consumer. Further, such a light generating system may facilitate providing (red) first device light with a relatively high energy-efficiency. Further, it may also be possible to deliberately allow some light source light to end up in the (first device) light as the UV light and / or ultraviolet light may also have beneficial effects in terms of color perception or possible advantageous effects in relation to health and / or reduction in bacterial and / or viral load.

[0010] The light generating system may especially be configured to generate system light. The system light may essentially consist of the first device light in embodiments wherein there are no further sources of light. However, the system may also comprise further sources or light. Hence, in embodiments, the system light may comprise first device light and / or light of one or more other sources of light, like one or more further light generating devices. Here below, the invention will first be described in general, with attention to the first light generating device and to the luminescent converter.

[0011] The first light generating device may comprise a light source. Here below, some embodiments are described in relation to light generating devices and light sources in general; i.e. thus with reference to the first light generating device and to optional further light generating devices.

[0012] The term “light source” may in principle relate to any light source known in the art. In a specific embodiment, the light source may comprise an LED. The term “light source” may also relate to a plurality of (essentially identical (or different)) light sources, such as 2-2000 (LED) light sources. The phrase “different light sources”, and similar phrases, may refer to a plurality of solid-state light sources selected from at least two different bins. Likewise, the phrase “identical light sources”, and similar phrases, may refer to a plurality of solid-state light sources selected from the same bin. Hence, the term LED may also refer to a plurality of LEDs.

[0013] Further, the term “light source” may in embodiments also refer to a so-called chip-on-board (Cob) light source. The term “CoB” especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of light emitting semiconductor light sources may be configured on the same substrate. In embodiments, a CoB is a multi LED chip configured together as a single lighting module.

[0014] The term “light source” may also refer to a chip scale package (CSP) and / or a chip scale packaged (CSP) LED. A CSP may comprise a single solid state die (such as a LED) with provided thereon a luminescent material comprising layer. The term “light source” may also refer to a midpower package. A midpower package may comprise one or more solid state die(s). The die(s) may be covered by a luminescent material comprising layer. The die dimensions may be equal to or smaller than 2 mm, such as in the range of e.g. 0.2-2 mm. Herein, the term “light source” may also especially refer to a small solid-state light source, such as having a mini size or micro size. For instance, the light sources may comprise one or more of mini LEDs and micro LEDs, such as especially micro LEDs or “microLEDs” or “pLEDs”. Herein, the term mini size or mini LED especially refers to solid-state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm - 1 mm. Herein, the term p size or micro LED especially refers to solid- state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm and smaller.

[0015] The light source may have a light escape surface. For LEDs it may for instance be the LED die, or when a resin is applied to the LED die, the outer surface of the resin. The term escape surface especially relates to that part of the light source, where the light actually leaves or escapes from the light source. The light source is configured to provide a beam of light. This beam of light (thus) escapes from the light exit surface of the light source.

[0016] The term “light source” may refer to a semiconductor light-emitting device, such as an LED, a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc... The term “light source” may also refer to an organic light-emitting diode (OLED), such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). In an embodiment, the light source comprises a LED. The terms “light source” or “solid-state light source” may also refer to a superluminescent diode (SLED). Especially, the term “solid-state light source” may refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, a superluminescent diode, or a multi -junction diode. The light source may comprise one or more micro-optical elements (array of micro lenses) downstream of a single solid-state light source, or downstream of a plurality of solid-state light sources (i.e. e.g. shared by multiple LEDs). In embodiments, the light source may comprise a LED with on-chip optics. The light source may comprise pixelated single LEDs (with or without optics) (offering in embodiments on-chip beam steering). In embodiments, the light source may be a dc-LED. Alternatively, the light source may be a pc-LED. Hence, the term “light source” may refer to a light generating element as such, like e.g. a solid-state light source, or e.g. to a package of the light generating element, such as a solid-state light source, and one or more optics, like a lens, a collimator. In embodiments, the term “light source” may also refer to a combination of a light source, like an LED, and an optical filter, which may change the spectral power distribution of the light generated by the light source. In specific embodiments, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED or multi -junction (light emitting) diode. The light source may especially be configured to generate light source light having an optical axis (O), (a beam shape,) and a spectral power distribution. The light source light may in embodiments comprise one or more bands, having band widths as known for lasers

[0017] The term “laser light source” especially refers to a laser. Such laser may especially be configured to generate laser light source light having one or more wavelengths in the UV, visible, or infrared, especially having a wavelength selected from the wavelength range of 200-2000 nm, such as from the wavelength range of 300-1500 nm. The term “laser” especially refers to a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Especially, the term “laser” may refer to a solid-state laser. In specific embodiments, the terms “laser” or “laser light source”, or similar terms, may refer to a laser diode (or diode laser). Hence, in embodiments the light source comprises a laser light source. In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of a semiconductor laser diodes, such as GaN, InGaN, AlGalnP, AlGaAs, InGaAsP, lead salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc. The term “solid state material laser”, and similar terms, may thus refer to a solid state laser like based on a crystalline or glass body dopes with ions, like transition metal ions and / or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser, etc.

[0018] Especially, the term “light source” herein may refer to a solid-state light source, more especially an LED.

[0019] As indicated above, in embodiments, the first light generating device may comprise one or more light sources. The phrase “one or more light sources” may refer to a single light source or to a plurality of light sources. Further, this term may refer to a single light source of a single type (e.g. single wavelength bin), a plurality of light sources of a single type (e.g. single wavelength bin), or it may refer to two or more light sources including at least two different light sources (e.g. of different wavelength bins). One or more light sources of a single type may provide essentially a single peak having a single peak emission wavelength, whereas light sources of two or more different types may provide two or more different peaks having two or more (different) peak emission wavelengths.

[0020] Especially, the one or more light sources may be configured to generate light source light having a peak emission wavelength in a wavelength range of 280-420 nm. Alternatively or additionally, in embodiments, at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 280- 420 nm wavelength range, like at least 95%. The phrase “a peak emission wavelength in a wavelength range” (like e.g. the 280-420 nm wavelength range), and similar phrases, may refer to a spectral power distribution in that wavelength range (like e.g. the 280-420 nm wavelength range) with a single emission band, and thus a single peak emission wavelength, but may also refer to a spectral power distribution in that wavelength range (like e.g. the 280- 420 nm wavelength range) with two or more emission bands, and thus two or more peak emission wavelengths. The term “peak emission wavelength”, and similar terms, may refer to a wavelength where the radiometric emission spectrum of the light source reaches a maximum, i.e., the peak emission wavelength may denote the wavelength at which a peak is observed in a graph of the spectral power distribution. Would a spectral power distribution comprise two or more emission bands, a first emission band may define a first peak emission wavelength, and a second emission band may define a second peak emission wavelength, wherein the (light) intensity at the first peak emission wavelength may in embodiments be equal to or differ from the (light) intensity at the second peak emission wavelength. In embodiments, adjacent peak emission may at least partly overlap.

[0021] Downstream of the light source, a luminescent converter may be configured. In specific embodiments, the invention provides a light generating system comprising a first light generating device and a luminescent converter. Especially, the luminescent converter may be configured in a light receiving relationship with the one or more solid-state light sources. Further, the invention provides a light generating system comprising a first light generating device, wherein the first light generating device comprises a luminescent converter.

[0022] As indicated above, the light generating system (such as especially the first light generating device) may further comprise a luminescent converter. The luminescent converter may be configured in a light receiving relationship with the one or more solid-state light sources. Especially, the luminescent converter may be configured downstream from the one or more solid-state light sources. The terms “downstream” and “upstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here especially the one or more solid-state light sources), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”. In embodiments, the first light generating device may (thus) comprise the luminescent converter and the one or more solid-state light sources.

[0023] The luminescent converter may be configured in physical contact and covering (a light escape surface of) the one or more solid-state light sources. That is, the luminescent converter may be configured as a coating. Hence, in specific embodiments, the luminescent converter may be configured as a coating, wherein the luminescent converter may be configured covering and in physical contact with the one or more solid-state light sources. Configuring the luminescent converter as a coating may improve the efficiency with which the light source light is coupled into the luminescent converter, as the light source light may be (essentially) not be refracted at a first interface between the one or more solid-state light sources and air, and at a second interface between air and the luminescent converter.

[0024] Alternatively, the luminescent converter may be configured as a self- supporting luminescent body. In such embodiments, the luminescent converter may be configured: (i) in physical contact with the one or more solid-state light sources, or (ii) at a non-zero distance di from (the light escape surfaces of) the one or more solid-state light sources. The non-zero distance di may be selected from the range of > 5 pm, such as from the range of > 10 pm, especially from the range of > 25 pm. Additionally or alternatively, the non-zero distance di may be selected from the range of < 10 cm, such as from the range of < 5 cm, especially from the range of < 1 cm. The luminescent converter may be physically separated from the one or more solid-state light sources.

[0025] In embodiments, the luminescent converter may have a first major face and a second major face, wherein the second major face may be configured opposite the first major face.

[0026] In embodiments, the light source light may be incident on the first major face of the luminescent converter, and the first luminescent material light (and optionally transmitted light source light) may exit the luminescent converter via the second major face. Hence, in specific embodiments, the luminescent converter may be configured in a transmissive mode. Herein, the term “transmissive mode” may indicate that when at least part of the (first) light source light is propagating in the same direction from the luminescent converter as it was propagating to the luminescent converter directly upstream of the luminescent converter, it may have a direction overlapping with the direction in which the (first) luminescent material light escapes from the light generating system. Configuring the luminescent converter in the transmissive mode may facilitate providing the luminescent converter as a coating on the one or more solid-state light sources. Further, configuring the luminescent converter in the transmissive mode may simplify the construction of the light generating system, as no optical elements such as reflectors and / or (dichroic) beam splitters are required to guide the luminescent material light to a light exit of the light generating system.

[0027] Yet, in alternative embodiments, the luminescent converter may be configured in a reflective mode. Herein, the term “reflective mode” may indicate that when (first) light source light is reflected at the luminescent converter, it may have a direction overlapping with the direction in which the luminescent material light escapes from the system. Hence, in the reflective mode, the light source light may be incident on the first major face of the luminescent converter, and the first luminescent material light (and reflected light source light) may exit the luminescent converter via the first major face. Configuring the luminescent converter in the reflective mode may improve thermal management, as the absorption and conversion of light may be spread over a larger optical path length within the luminescent converter. Further, as the path length of the light source light in the luminescent converter may be doubled in the reflective mode, the reflective mode may facilitate reducing one or more of the concentration of luminescent materials in and the thickness of the luminescent converter. In the reflective mode, the second major face of the luminescent converter may comprise a reflective coating. Alternatively, in the reflective mode, the luminescent converter may be configured in physical contact with a reflective mirror at the second major face.

[0028] The luminescent converter may comprise one or more luminescent materials, such as especially at least a first luminescent material. The term “luminescent material” may especially refer to a material that can convert first radiation, especially one or more of UV radiation, blue radiation, and green radiation, into second radiation. Herein, UV (ultraviolet) may refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm, though other wavelengths may also be possible. The term “violet light”, and similar terms, may especially relate to light having a wavelength in the range of about 380-440 nm. Further, the term “blue light”, and similar terms, may especially relate to light having a wavelength in the range of about 440-490 nm. The first radiation and second radiation may have different spectral power distributions, with the second radiation generally having a spectral power distribution at larger wavelengths than the first radiation (i.e. “down-conversion”). In embodiments, the “luminescent material” may especially refer to a material that can convert radiation into e.g. visible and / or infrared light. The terms “visible light” or “visible emission”, and similar terms, refer to light having one or more wavelengths in the range of about 380-780 nm. Further, IR (infrared) may especially refer to radiation having a wavelength selected from the range of 780-3000 nm, such as 780-2000 nm, e.g. a wavelength of < 1500 nm, like a wavelength of > 900 nm, though other wavelengths may be possible. For instance, in embodiments the luminescent material may be able to convert one or more of UV radiation, blue radiation, and green radiation, into visible light. Hence, upon excitation with radiation, the luminescent material may emit radiation. In general, the luminescent material will be a down converter, i.e. radiation with a smaller wavelength is converted into radiation with a larger wavelength (Xex<Xem). In embodiments, the term “luminescence” may refer to phosphorescence. In embodiments, the term “luminescence” may also refer to fluorescence. Instead of the term “luminescence”, also the term “luminescent material light” or “emission” may be applied. Hence, the terms “first radiation” and “second radiation” may refer to excitation radiation and emission (radiation), respectively. Likewise, the term “luminescent material” may in embodiments refer to phosphorescence and / or fluorescence. The term “luminescent material” may also refer to a plurality of different luminescent materials. Examples of possible luminescent materials are indicated below. Hence, the term “luminescent material” may in specific embodiments also refer to a luminescent material composition. Instead of the term “luminescent material” also the term “phosphor” may be applied. These terms are known to the person skilled in the art.

[0029] In embodiments, luminescent materials may be selected from garnets and nitrides, especially doped with trivalent cerium or divalent europium, respectively. However, other types of luminescent materials are herein not excluded. The term “nitride” may also refer to oxynitride or nitridosilicate, etc. Alternatively or additionally, the luminescent material(s) may be selected from silicates, especially doped with divalent europium. In embodiments, the luminescent material may comprise a divalent europium comprising oxynitride luminescent material. Further, in embodiments, the luminescent material may comprise a divalent europium comprising nitride luminescent material.

[0030] In embodiments, the luminescent material may comprise a luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc; and wherein the light source light may comprise blue light source light. Especially, A may comprise one or more of Y, Gd and Lu, such as especially one or more of Y and Lu. Especially, B may comprise one or more of Al and Ga, more especially at least Al, such as essentially entirely Al. Hence, especially suitable luminescent materials are cerium comprising garnet materials. Embodiments of garnets especially include A3B5O12 garnets, wherein A comprises at least yttrium (Y) or lutetium (Lu) and wherein B comprises at least aluminum (Al). Such garnets may be doped with cerium (Ce), with praseodymium (Pr) or a combination of cerium and praseodymium; especially however with Ce. Especially, B may comprise aluminum (Al), with optionally gallium (Ga) and / or scandium (Sc) and / or indium (In) up to about 20% of B, more especially up to about 10 % of B (i.e. the B ions essentially consist of > 90 mole % of Al and < 10 mole % of one or more of Ga, Sc, and In). B may especially comprise up to about 10% gallium. In another variant, B and O may at least partly be replaced by Si and N. The element A may especially be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Further, Gd and / or Tb are especially only present up to an amount of about 20% of A. In a specific embodiment, the garnet luminescent material comprises (Yi- xLux)3BsOi2:Ce, wherein 0 < x < 1. The term “:Ce”, indicates that part of the metal ions (i.e. in the garnets: part of the “A” ions) in the luminescent material is replaced by Ce. This is known to the person skilled in the art. Ce will replace A in general for not more than 10%; in general, the Ce concentration will be in the range of 0.1 to 4%, especially 0.1 to 2% (relative to A). Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art. In embodiments, such luminescent materials may have a suitable spectral distribution, have a relatively high efficiency, and have a relatively high thermal stability.

[0031] In specific embodiments, the luminescent material may comprise (YxiA’x2Cex3)3(AlyiB’y2)5Oi2. Here, A’ comprises one or more elements selected from the group consisting of lanthanides, and B’ comprises one or more elements selected from the group of Ga, In and Sc, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2. Especially, x3 is selected from the range of 0.001-0.1. Note that in embodiments x2=0. Alternatively or additionally, in embodiments y2=0.

[0032] In embodiments, the luminescent material may comprise a luminescent material of the type AsSieNiuCe3, wherein A comprises one or more of Y, La, Gd, Tb and Lu, such as in embodiments one or more of La and Y. In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu2+and / or NESis Eu2and / or MAlSiN3:Eu2+and / or Ca2AlSi3O2Ns:Eu2+, etc., wherein M comprises one or more of Ba, Sr and Ca, especially in embodiments at least Sr. Hence, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations, as is known to the person skilled in the art. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions (indicated by M) is replaced by Eu (in these examples by Eu2+). For instance, assuming 2% Eu in CaAlSi Eu, the correct formula could be (Cao.98Euo.o2)AlSiN3.

[0033] The term “luminescent material” herein especially relates to inorganic luminescent materials. Alternatively or additionally, also other luminescent materials may be applied. For instance quantum dots and / or organic dyes may be applied and may optionally be embedded in transmissive matrices like e.g. polymers, like PMMA, or polysiloxanes, etc.. In embodiments, the luminescent material may comprise a luminescent material of the type Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux. Herein, M may comprise one or more of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), such as especially one or more of Ca, Sr, and Ba. Hence, Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Euxmay especially refer to (Mg,Ca,Sr,Ba)i-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux. Such a luminescent material may be indicated as an SLA-type phosphor, or SLA phosphor. Luminescent materials of the type Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux may be described in US2021171827A1, which is hereby herein incorporated by reference. In Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, x may be selected from the range of 0 < x < 0.1, such as from the range of 0.0005 < x < 0.08, especially from the range of 0.001 < x < 0.05. Hence, europium (Eu) may not replace more than 10% of the cation M, and may substantially or only be in the divalent state (Eu2+), as is known to the person skilled in the art. Further, in Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, y may be selected from the range of 0 < y < 1, such as from the range of 0 < y < 0.75, especially from the range of 0 < y < 0.6. In specific embodiments, y = 0. In Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, z may be selected from the range of 0 < z < 0.1, such as from the range of 0 < z < 0.07, especially from the range of 0 < z < 0.05. Hence, in embodiments, in an SLA phosphor, SiN may replace A1O to a maximum of 10 mole%. In embodiments, an SLA phosphor may crystallize in a UCr4C4 type crystal structure. Hence, the luminescent material may comprise a luminescent material of the type Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, wherein M comprises one or more of Ca, Sr, and Ba, wherein 0 < x < 0.04, wherein 0 < y < 1, wherein 0 < z < 0.05, and wherein y + z < 1.

[0034] Further, the luminescent material may comprise a SiAlON phosphor, such as selected from the group comprising (a) S112— m— n Alm+nOnNi6-n:Eu2+(a-SiA10N), (b) Si6-nAlnOnN8-n:Eu2+, wherein 0 < n < 4.2 (P-SiAlON), and (c) Si2-nAlnOi+nN2-n:Eu2+, wherein 0 < n < 0.2 (O-SiAlON).

[0035] In embodiments, the luminescent material may comprise a tetravalent manganese-comprising luminescent material, i.e., a luminescent material doped with tetravalent manganese. Especially, in embodiments, the luminescent material may comprise a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x may be selected from the range of 0-1, wherein A comprises a tetravalent cation, for instance comprising one or more of silicon and titanium, and wherein X comprises a monovalent anion, at least comprising fluorine. Such luminescent materials may herein also be indicated as “KSiF” or “KSF”, regardless of the composition of M’, M, A, and X. A luminescent material of the type M’XM2-2XAX6 doped with tetravalent manganese is amongst others described in WO2013121355A1, which is herein incorporated by reference. Passages from WO2013121355A1 are also copied herein. In embodiments, the alkaline earth cation M’ may comprise one or more of magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba. Further, the alkaline cations M may comprise one or more of sodium (Na), potassium (K) and rubidium (Rb). Optionally, M may (further) comprise one or more of ammonium (NHZ), lithium (Li), and cesium (Cs). In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. The phrase “wherein M comprises at least potassium” indicates for instance that of all M cations in a mole M’xM2-2xAX6 , a fraction comprises K+and an optionally remaining fraction comprises one or more other monovalent (alkaline) cations (see also below). In another preferred embodiment, M comprises at least potassium and rubidium. Optionally, the M’xM2-2xAX6 luminescent material has the hexagonal phase. In yet another embodiment, the M’xM2-2xAX6 luminescent material has the cubic phase. In an embodiment, a combination of different alkaline cations M may be applied. In yet another embodiment, a combination of different alkaline earth cations M’ may be applied. In yet another embodiment, a combination of one or more alkaline cations M and one or more alkaline earth cations M’ may be applied. For instance, KRbo.sSro^sAXe might be applied. As indicated above, x in the formula M’xM2-2xAX6 may be selected from the range of 0-1, especially x < 1. In specific embodiments, x = 0.

[0036] The term “tetravalent manganese” refers to Mn4+. This is a well-known luminescent ion. In the formula as indicated above, part of the tetravalent cation A (such as Si) is being replaced by manganese. Hence, M’xM2-2xAX6 doped with tetravalent manganese may also be indicated as M’xM2-2xAi-mMnmX6 (or M’xM2-2xAX6:Eu). The mole percentage of manganese, i.e. the percentage it replaces the tetraval ent cation A will in general be in the range of 0.1-15 %, especially 1-12 %, i.e. m is in the range of 0.001-0.15, especially in the range of 0.01-0.12. As manganese replaces part of a host lattice ion and has a specific function, it is also indicated as “dopant” or “activator”. Hence, the hexafluorosilicate is doped or activated with manganese (Mn4+).

[0037] In embodiments, A may comprise a tetravalent cation, and preferably at least comprises silicon. A may optionally (further) comprise one or more of titanium (Ti), germanium (Ge), stannum (Sn) and zinc (Zn). Preferably, at least 80%, even more preferably at least 90%, such as at least 95% of A consists of silicon. In a specific embodiment, M’XM2- 2xAXe can also be described as (Ki-r-i-n-c-nhRbrLiiNanCsc(NH4)nh)2AX6, wherein r is in the range of 0-1, wherein l,n,c,nh are each individually preferably in the range of 0-1, preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0- 0.05, and wherein r+l+n+c+nh is in the range of 0-1, especially 1+n+c+nh < 1, especially < 0.2, preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05. X is preferably fluorine (F). Further, in a specific embodiment, M’XM2- 2XAXe can also be described as MgmgCaCaSrsrBaba(KkRbrLiiNanCsc(NH4)nh)2AX6, with k, r, 1, n, c, nh each individually being in the range of 0-1, wherein mg, ca, sr, ba are each individually in the range of 0-1, and wherein mg+ca+sr+ba+k+ r+ l+n+c+nh=l. In embodiments, k=l, and the others (mg, ca, sr, ba, r, 1, n, c, nh) are zero.

[0038] As indicated above, X relates to a monovalent anion, but at least comprises fluorine. Other monovalent anions that may optionally be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). Preferably, at least 80%, even more preferably at least 90%, such as 95% of X consists of fluorine. Hence, in a specific embodiment, M’xM2-2xAX6 can also be described as M’xM2-2XA(Fi.ci-b-iClciBrbIi)6, wherein cl,b,i are each individually preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05, and wherein cl+b+i < 1, especially < 0.2, preferably in the range of 0-0.2, especially in the range of 0-0.1, even more especially in the range of 0-0.05. Hence, M’xM2-2XAX6 can also be described as (Ki-r-i-n-c-nh RbrLiiNanCsc(NH4)nh)2Sii-m-t-g-s-zrMnmTitGegSnsZrzr(Fi-ci-b-iClciBrbIi)6, with the values for r,l,n,c,nh,m,t,g,s,zr,cl,b,i as indicated above.

[0039] In an embodiment, M’xM2-2XAX6 comprises BGSiFe (indicated herein also as KSiF system). In another preferred embodiment, M’xM2-2XAX6 comprises KRbSiFe (herein also indicated as K,Rb system). In specific embodiments, the indication M’xM2-2XAX6 may refer to one or more of (K,Rb)2SiFe:Mn4+, (K,Rb)2TiFe:Mn4+, K2(Si,Ti)Fe:Mn4+, and Rb2(Si,Ti)Fe:Mn4+, such as one or more of K2TiFe:Mn4+, of K2SiFe:Mn4+, and of Rb2SiFe:Mn4+. As can be derived from the above, “(Si,Ti)” may indicate one or more of Si and Ti. Hence, in specific embodiments, the luminescent material may comprise one or more of (K,Rb)2SiFe:Mn4+and K2(Si,Ti)Fe:Mn4+. The luminescent material may also be coated, as also described in WO2013121355A1.

[0040] Hence, when M (or A) in chemical formulas refer to n different elements, this may imply that the relevant formula may comprise for the M (or A) position in the formula essentially any permutation of the n different elements. For instance, when M=Ba,Sr,Ca or when M comprises one or more of Ba, Sr, Ca or when M refers to Ba,Sr,Ca, i.e. n=3, this may imply that in the formula Ba, Sr, Ca, (BaxSry), (BaxCay), (CaxSry), or (BaxSryCaz), may be available, wherein in general x+y+z=l.

[0041] Referring to e.g. M’xM2-2XAXe, this may refer to e.g. one or more of K2SiFe:Mn4+and of Rb2SiFe:Mn4+, or (KxRby)2SiFe:Mn4+, etc. Referring to (Ba,Sr,Ca)AlSiN3:Eu, this may imply BaAlSiN3:Eu, SrAlSiN3:Eu, CaAlSiN3:Eu, (BaxSry)AlSiN3:Eu, (BaxCay)AlSiN3:Eu, (CaxSry)AlSiN3:Eu, or (BaxSryCaz)AlSiN3:Eu. Referring to e.g. A3BsOi2:Ce, wherein A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, this may imply Y3BsOi2:Ce, La3BsOi2:Ce, GdBsOn Ce, TbsBsOn Ce, Lu3BsOi2:Ce, but also e.g. (Yx,Gdy)3B50i2:Ce, (Yx,Luy)3B50i2:Ce, (Gdx,Luy)3B50i2:Ce, (Yx,Gdy,Luz)3B50i2:Ce, etc. etc., with hereby only limiting for the sake of economy to unary, binary, and ternary examples, though quaternary and higher examples are not excluded herein.

[0042] Further, indications like “K,Rb” or Ba,Sr,Ca, and similar indications (see also above), may indicate one or more of such elements. Hence, (K,Rb)2SiFe:Mn4+, may e.g. refer to K2SiFe:Mn4+and of Rb2SiFe:Mn4+, or (KxRby)2SiFe:Mn4+. Also herein in general x+y=l. Hence, when M (or A) may refer to n different elements, with n being at least two, 2n-l permutations may in principle be possible.

[0043] In embodiments, the first luminescent converter may (at least) comprise a first luminescent material. The first luminescent material may comprise any (combination) of the luminescent materials indicated above. The first luminescent material may comprise a quantum structure, such as a quantum dot, or such as a quantum rod. Quantum structures may for instance comprise (such as be based on) one or more of cadmium (Cd), indium (In), zinc (Zn), silver (Ag), and lead (Pb). Further, the first luminescent material may comprise a luminescent material of the type M’xM2-2XAXe doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, wherein A comprises a tetravalent cation, and wherein X comprises a monovalent anion, at least comprising fluorine. The first luminescent material may thus comprise a luminescent material of the type M’xM2-2XA(F,Cl,Br,I)6 doped with tetraval ent manganese, wherein x may especially be in the range of 0-1. As can be derived from the above, the indication “(F,Cl,Br,I)” may refer to one or more of F, Cl, Br, and I, but may especially refer to at least F, and optionally one or more of Cl, Br, and I (see also above, wherein it is indicated that cl+b+i < 1). In specific embodiments, the first luminescent material may be a luminescent material of the type M’XM2-2XAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, wherein X comprises a monovalent anion, at least comprising fluorine. In embodiments, the first luminescent material may comprise, such as be, a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein A may (at least) comprise one or more of silicon (Si), titanium (Ti), and germanium (Ge). In embodiments, A may (at least) comprise Si. Additionally or alternatively, A may (at least) comprise Ge. Further, additionally or alternatively, A may (at least) comprise Ti. Hence, in specific embodiments, the first luminescent material may be a luminescent material of the type M’XM2-2XAX6 doped with tetravalent manganese, wherein A may comprise one or more of titanium and germanium.

[0044] In embodiments, M in the formula M’xM2-2xAX6:Mn4+may comprise one or more of Na, K, Rb, NH , Li, and Cs. Especially, M may comprise one or more of K and Rb. Further, as indicated above, A may comprise one or more of Si, Ge, and Ti. Hence, in embodiments, the first luminescent material may comprise (K,Rb)2(Si,Ge,Ti)Fe:Mn4+. The first luminescent material may comprise (KaRbb)2(SixTiyGez)F6:Mn4+, wherein a + b = 1, wherein a > 0 and b > 0, wherein x + y + z = 1, and wherein x > 0, y > 0, and z > 0. Especially, in such embodiments, y + z > 0.4, such as y + z > 0.6, especially y + z > 0.8, including (essentially) y + z = 1. Further, in such embodiments, a may be (essentially) 1, and b may be (essentially) 0. Hence, in embodiments, the first luminescent material may comprise, such as be, K2(SixTiyGez)F6:Mn4+, wherein x > 0, y > 0, z > 0, x + y + z = 1, and y + z > 0.4, such as y + z > 0.6, especially y + z > 0.8, including (essentially) y + z = 1. Herein, terms such as “x + y + z = 1”, and similar terms, may especially indicate x + y + z > 0.99, such as x + y + z > 0.995, especially x + y + z > 0.998. That is, in K2AFe:Mn4+, wherein A is SixTiyGez, and x + y + z = l, A may consist of one or more of Si, Ti, Ge, and optionally impurities to an amount of < 1%, such as < 0.5%, especially < 0.2%, of A. Similarly, in M2(SixTiyGez)Fe:Mn4+, wherein M is KaRbb, and a + b = 1, M may consist of one or more of K, Rb, and optionally impurities to an amount of < 1%, such as < 0.5%, especially < 0.2%, of M. Hence, in specific embodiments, the first luminescent material may comprise K2(SixTiyGez)Fe:Mn4+, wherein x > 0, y > 0, z > 0, x + y + z = 1, and y + z > 0.6 may apply. Dependent upon the chemical composition of the (first) luminescent material, the absorption may be higher or lower at specific wavelengths (see also Fig. 2, vide infra).

[0045] The first luminescent material may thus comprise K2(SixTiyGez)F6:Mn4+, wherein x > 0, y > 0, z > 0, and x + y + z = l. In embodiment, the first luminescent material may comprise mostly Ti as the tetravalent cation. That is, in embodiments, the first luminescent material may comprise K2(SixTiyGez)F6:Mn4+, wherein x > 0, z > 0, x + y + z = 1, and y > 0.6, such as y > 0.8, especially y > 0.9, including (essentially) y = 1. Hence, in specific embodiments, (the first luminescent material may comprise K2(SixTiyGez)F6:Mn4+, wherein) y > 0.8. A first luminescent material comprising mostly Ti as the tetravalent cation may have a more red-shifted absorption spectrum compared to a first luminescent material comprising a lower amount of Ti.

[0046] Alternatively (or additionally), the first luminescent material may comprise a luminescent material of the type K2(SixTiyGez)Fe:Mn4+, wherein x > 0.5, such as x > 0.7, especially x > 0.9, like (essentially) K2SiFe:Mn4+(x = 1). Hence, in specific embodiments, the first luminescent material may comprise K2SiFe:Mn4+. A luminescent material of the type K2(SixTiyGez)Fe:Mn4+comprising (essentially) only Si as the tetravalent cation may provide luminescent material light having a more red-shifted centroid wavelength compared to a luminescent material wherein the tetravalent cation comprising one or more of Ti and Ge. Further, such a luminescent material may have a relatively high absorption in the wavelength range of 280-420 nm (compared to a luminescent material comprising e.g. Ti as the tetravalent cation). Hence, such a luminescent material may have an improved absorption for the light source light. Yet, in embodiments, the first luminescent material may comprise a luminescent material of the type K2(SixTiyGez)Fe:Mn4+, wherein x + y + z = 1, wherein x > 0, y > 0, z > 0, and wherein x + z > 0.3, such as x + z > 0.5, especially x + z > 0.7.

[0047] As indicated above, the first luminescent material may comprise a combination of luminescent materials. Hence, in embodiments, the first luminescent material may comprise a luminescent material of the type M’xM2-2XAXe:Mn4+and a quantum structure (such as especially a quantum dot). Alternatively, the first luminescent material may (essentially) consist of one or more luminescent materials of the type M’xM2-2XAXe:Mn4+, wherein the one or more luminescent materials of the type M’xM2-2XAXe:Mn4+may differ in one or more of the composition of M and A. For instance, the first luminescent material may comprise a primary first luminescent material of the type (K,Rb)2(SixTiyGez)Fe:Mn4+, wherein y + z > 0.5, and a secondary first luminescent material of the type (K,Rb)2(SixTiyGez)Fe:Mn4+, wherein y + z < 0.5.

[0048] As can be derived from the above, M may comprise in embodiments an alkaline cation. Especially, in embodiments M may comprise one or more of K and Rb. Further, in embodiments, A may comprise one or more of Si, Ti, Ge, Sn, and Zr. Furthermore, in embodiments, x=0. Moreover, in embodiments, the first luminescent material may comprise (Rb,K)2(Si Ti,Ge)Fe:Mn4+. In specific embodiments, the first luminescent material comprises a luminescent material of the type M’xM2-2xAX6 doped with Mn4+. More especially, the first luminescent material is a luminescent material of the type M’xM2-2xAX6 doped with Mn4+. The phrase “the first luminescent material is a luminescent material of the type M’xM2-2xAX6 doped with Mn4+”, and similar phrases, may refer to embodiments wherein the first luminescent material consists of a single type of M’xM2-2xAX6 doped with Mn4+, like K2SiFe:Mn4+, but may also refer to embodiments wherein the first luminescent material consists of two or more phosphors of the type of M’xM2-2xAX6 doped with Mn4+, like K2SiF6:Mn4+and K2TiF6:Mn4+, etc.

[0049] In embodiments, the first luminescent material may be configured to convert at least part of the light source light received by the first luminescent material into first luminescent material light. Especially, the first luminescent material may be configured to convert > 50%, such as > 60%, especially > 70%, of (a spectral power of) the light source light received by the first luminescent material into first luminescent material light. Further, the first luminescent material may be configured to convert > 80%, such as > 90%, especially > 95%, like > 98%, including (essentially) 100%, of (a spectral power of) the light source light received by the first luminescent material into first luminescent material light. Hence, in specific embodiments, the first luminescent material may be configured to convert at least 98% of the light source light received by the first luminescent material into first luminescent material light. Converting > 98% of (a spectral power of) the light source light received by the first luminescent material into first luminescent material light may facilitate providing first device light being (essentially) free from first light source light (see however also below). The first luminescent material light may have a first centroid wavelength (kcl).

[0050] The term “centroid wavelength”, also indicated as c, is known in the art, and refers to the wavelength value (in nm) where half of the light energy is at shorter and half the energy is at longer wavelengths. It is the wavelength that divides the integral of a spectral power distribution into two equal parts as expressed by the formula Ac = X I(k) / (S I( X)), where the summation is over the wavelength range of interest, and I (A) is the spectral energy density (i.e. the integration of the product of the wavelength and the intensity over the emission band normalized to the integrated intensity). The centroid wavelength may e.g. be determined at operation conditions.

[0051] In embodiments, the first centroid wavelength (kc l ) may be selected from the range of 600-660 nm, like from the range of 610-650 nm, such as from the range of 620-640 nm. Hence, in embodiments, the first luminescent material light may comprise, such as be, one or more of orange light and red light, such as especially red light. The terms “orange light” or “orange emission”, and similar terms, may especially relate to light having a wavelength in the range of about 590-620 nm. The terms “red light” or “red emission”, and similar terms, may especially relate to light having a wavelength in the range of about 620- 780 nm. The phrase “in the orange-red wavelength range”, and similar phrases (like orange and red wavelength range), may indicate spectral power at one or more wavelengths in the orange wavelength range and / or spectral power at one or more wavelengths in the red wavelength range. The orange-red wavelength range is defined as the 590-750 nm wavelength range.

[0052] Further, the first luminescent material light may comprise at least one emission band having a first full width at half maximum FWHM1 of < 65 nm, such as < 55 nm, especially < 40 nm. Further, the first luminescent material light may comprise at least one emission band having a first full width at half maximum FWHM1 of < 35 nm, such as < 30 nm, especially < 25 nm. Additionally or alternatively, the first luminescent material light may comprise the at least one emission band having a first full width at half maximum FWHM1 of > 2 nm, such as > 5 nm, especially > 7 nm. In embodiments, the first luminescent material light may comprise a plurality of emission bands, wherein at least one band may have the first full width at half maximum FWHM1. Additionally or alternatively, the first luminescent material light may comprise a plurality of emission bands, wherein essentially all of the emission bands may have the first full width at half maximum FWHM1. The term “emission band” may refer to the emission (spectral power distribution) resulting from a radiative transition of electrons from (vibrational levels of) a first higher-energy excited state to (vibrational levels of) a second lower-energy (ground) state, wherein a larger number of vibrational levels in (one or more of) the first excited state and second (ground) state results in a broader emission band (spanning a larger wavelength range). Further, the term “full width at half maximum” (or “FWHM”) refers to the width of (the spectral power distribution of) the emission band at half the maximum intensity of said emission band. The FWHM of an emission band may especially be determined at room temperature. Hence, in embodiments the first luminescent material light may have a centroid wavelength (kc l ) selected from the wavelength range of 610-650 nm, and may comprise one or more emission bands having a full width half maximum (FWHM1) of at maximum 50 nm.

[0053] The luminescent converter may comprise the first luminescent material in a first concentration Ci. In embodiments, Ci may be selected from the range of > 8 vol%, such as from the range of > 10 vol%, especially from the range of > 12 vol%, like from the range of > 15 vol%. Additionally or alternatively, Ci may be selected from the range of < 40 vol%, such as from the range of < 35 vol%, especially from the range of < 30 vol%, like from the range of < 25 vol%. Further, in embodiments, the first concentration Ci may be selected from the range of 8-40 vol%, such as from the range of 10-35 vol%, especially from the range of 12-30 vol%, like from the range of 15-25 vol%. Hence, in specific embodiments, the luminescent converter may comprise the first luminescent material in a first concentration Ci, wherein the first concentration Ci may be selected from the range of 12-30 vol%. Such a first concentration Ci may facilitate that the first luminescent material may be configured to convert > 50%, such as > 70%, especially > 90%, of (a spectral power of) the light source light received by the first luminescent material into first luminescent material light. Would there be different first luminescent materials, then the first concentration may be considered the overall concentration for all the first luminescent materials.

[0054] As indicated above, in embodiments the luminescent converter may be configured in the transmissive mode. Further, in embodiments, the luminescent converter may comprise a first luminescent material. Especially, the first luminescent material may comprise a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese (more especially is a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese). Furthermore, in embodiments, M’ may comprise an alkaline earth cation, M may comprise a monovalent cation, x may be in the range of 0-1, A may comprise a tetravalent cation. Further, in embodiments, X may comprise a monovalent anion, at least comprising fluorine. Especially, the first luminescent material may be configured to convert at least part of the light source light into first luminescent material light.

[0055] Especially, in embodiments, the first light generating device may be configured to generate first device light comprising the first luminescent material light. Moreover, in embodiments, the first device light may in embodiments be red light.

[0056] The terms “red light” or “red emission”, and similar terms, may especially relate to light having a wavelength in the range of about at least 600 nm, such as in the range of about 620-780 nm. In specific embodiments, the red light may have a centroid wavelength of at least 610 nm, like in the 620-780 nm wavelength range.

[0057] The terms “violet light” or “violet emission”, and similar terms, may especially relate to light having a wavelength in the range of about 380-440 nm. In specific embodiments, the violet light may have a centroid wavelength in the 380-440 nm range. The terms “blue light” or “blue emission”, and similar terms, may especially relate to light having a wavelength in the range of about 440-490 nm (including some violet and cyan hues). In specific embodiments, the blue light may have a centroid wavelength in the 440-490 nm range. The terms “green light” or “green emission”, and similar terms, may especially relate to light having a wavelength in the range of about 490-560 nm. In specific embodiments, the green light may have a centroid wavelength in the 490-560 nm range. The terms “yellow light” or “yellow emission”, and similar terms, may especially relate to light having a wavelength in the range of about 560-590 nm. In specific embodiments, the yellow light may have a centroid wavelength in the 560-590 nm range. The terms “orange light” or “orange emission”, and similar terms, may especially relate to light having a wavelength in the range of about 590-620 nm. In specific embodiments, the orange light may have a centroid wavelength in the 590-620 nm range. The terms “cyan light” or “cyan emission”, and similar terms, especially relate to light having a wavelength in the range of about 490-520 nm. In specific embodiments, the cyan light may have a centroid wavelength in the 490-520 nm range. The terms “amber light” or “amber emission”, and similar terms, may especially relate to light having a wavelength in the range of about 585-605 nm, such as about 590-600 nm. In specific embodiments, the amber light may have a centroid wavelength in the 585-605 nm range. The phrase “light having one or more wavelengths in a wavelength range” and similar phrases may especially indicate that the indicated light (or radiation) has a spectral power distribution with at least intensity or intensities at these one or more wavelengths in the indicate wavelength range. For instance, a blue emitting solid-state light source will have a spectral power distribution with intensities at one or more wavelengths in the 440-495 nm wavelength range.

[0058] In further embodiments, the first light generating device may be configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm may be provided by the first luminescent material light and (ii) in a range of 0-40% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm may be provided by the light source light. For instance, in the transmissive mode, the thickness of the luminescent converter and the first concentration Ci (“volume percentage”) of the first luminescent material in the luminescent converter may be chosen such that between 0% and 40% of the light source light may be transmitted by the luminescent converter (i.e. thus including 0% and 40%). Hence, in embodiments the first light generating device may be configured such that the first device light has a spectral power distribution in a wavelength range of 380-780 nm, wherein (i) at least 60% of a spectral power is provided by the first luminescent material light (which may essentially be in the (orange and) red wavelength range, and (ii) in a range of 0-40% of the spectral power is provided by the light source light (which may be in the 380-420 nm wavelength range).

[0059] Note that the light source light is not necessarily in the 380-420 nm wavelength range (only), but may additionally or alternatively, be present in the 280-380 nm wavelength range. Hence, in embodiments the first light generating device may be configured such that the first device light has a spectral power distribution in a wavelength range of 280- 780 nm, wherein (i) at least 50% of a spectral power is provided by the first luminescent material light (which may essentially be in the (orange and) red wavelength range, and (ii) in a range of 0-50% of the spectral power is provided by the light source light (which may be in the 280-420 nm wavelength range). In specific embodiments, the first light generating device may be configured such that the first device light has a spectral power distribution in a wavelength range of 280-780 nm, wherein (i) at least 60% of a spectral power is provided by the first luminescent material light (which may essentially be in the (orange and) red wavelength range, and (ii) in a range of 0-40% of the spectral power is provided by the light source light (which may be in the 280-420 nm wavelength range). In specific embodiments, over the entire wavelength range of 280-780 nm, in the range of 0-20%, such as in the range of 0-1%, especially in the range of 0-2%, like in the range of 0-5% of the spectral power of that range is provided by (the spectral power in) the 280-420 nm wavelength range.

[0060] Hence, the invention also provides (in an aspect) (embodiments of) a light generating system comprising a first light generating device and a luminescent converter, wherein: (A) the first light generating device comprises one or more solid-state light sources; wherein the one or more solid-state light sources are configured to generate light source light having a peak emission wavelength in a wavelength range of 280-420 nm; (B) the luminescent converter is configured in a light receiving relationship with the one or more solid-state light sources; wherein the luminescent converter comprises a first luminescent material; wherein the first luminescent material is a luminescent material of the type M’XM2- 2XAXe doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an monovalent cation, x is in the range of 0-1, A comprises a tetravalent cation, and wherein X comprises a monovalent anion, at least comprising fluorine; wherein the first luminescent material is configured to convert at least part of the light source light into first luminescent material light, wherein the first luminescent material light has a first centroid wavelength (kcl) selected from the range of 610-650 nm and having a first full width at half maximum FWHM1 of < 50 nm; and (C) the first light generating device is configured to generate first device light comprising the first luminescent material light; wherein the first device light is red light; wherein the first light generating device is configured such that (i) at least 50% of a spectral power distribution of the first device light in a wavelength range of 280-780 nm is provided by the first luminescent material light, more especially at least 60% and (ii) in a range of 0-50% of the spectral power distribution of the first device light in the wavelength range of 280-780 nm is provided by the light source light, more especially selected from the range of 0-40%.

[0061] Note that the first luminescent material light may essentially have no spectral power below 380 nm. Note that in embodiments at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 280-420 nm wavelength range, like at least 95%, such as even 100%.

[0062] The thicker the luminescent converter and / or the higher the volume percentage, the lower the transmission of the light source light may be, including essentially zero percent. For instance, the thickness and volume percentage may be selected n times the thickness and volume percentage which would allow up to 2% transmission of the light source light, wherein n may e.g. be selected to be at least 1.5, like 1.5-3, such as 2. Assuming e.g. n to be 2, then either the thickness, or the volume percentage may be twice as high as would allow up to 2% transmission of the light source light through the luminescent converter.

[0063] In embodiments a dichroic filter may be applied in the optical path between the one or more light sources and the luminescent converter, wherein the dichroic filter is transmissive for the light source light, but reflective for the first luminescent material light.

[0064] Note, however, that in some embodiments intentionally some light source light may be transmitted through the luminescent converter to end up in the first device light.

[0065] In specific embodiments, the one or more light sources may be configured to generate light source light having a peak wavelength selected from the range of 400-420 nm. Would such (violet) light end up in de first device light, it may hardly shift the color point. Further, it may have some detrimental effect on bacteria. Alternatively or additionally, in embodiments, at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 400-420 nm wavelength range, like at least 95%.

[0066] Especially, the one or more light sources may be configured to generate light source light having a peak wavelength selected from the range of 380-400 nm. Would such (violet) light end up in de first device light, it may (also) hardly shift the color point. Further, it may have some detrimental effect on bacteria. Alternatively or additionally, in embodiments, at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 380-400 nm wavelength range, like at least 95%.

[0067] Further, in embodiments, the one or more light sources may be configured to generate light source light having a peak wavelength selected from the range of 315-380 nm. Would such (UV-A) light end up in de first device light, it may (also) hardly shift the color point. Further, it may have some detrimental effect on viruses and / or bacteria. Alternatively or additionally, in embodiments, at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 315-380 nm wavelength range, like at least 95%.

[0068] Especially, the one or more light sources may be configured to generate light source light having a peak wavelength selected from the range of 330-360 nm. Would such (UV-A) light end up in de first device light, it may (also) hardly shift the color point. Further, this radiation may still be well absorbed by the manganese-based luminescent material. Further, it may have some detrimental effect on bacteria. Alternatively or additionally, in embodiments, at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 330-360 nm wavelength range, like at least 95%.

[0069] Further, in embodiments, the one or more light sources may be configured to generate light source light having a peak wavelength selected from the range of 280-315 nm. Would such (UV-B) light end up in de first device light, it may (also) hardly shift the color point. Further, it may have some detrimental effect on viruses and / or bacteria. Yet, it may (also) be beneficial for vitamin D generation. Alternatively or additionally, in embodiments, at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 280-315 nm wavelength range, like at least 95%. Especially, the luminescent converter may in such embodiments be configured between (a) a dichroic filter in the optical path between the one or more light sources and the luminescent converter, wherein the dichroic filter is transmissive for light source light and reflective for luminescent material light, and (b) a dichroic filter downstream of the luminescent converter, wherein this dichroic filter is reflective for light source light and transmissive for luminescent material light. For instance, a stack of the former dichroic filter, the luminescent converter, and the latter dichroic filter may be provided.

[0070] Further, in embodiments wherein (a) the one or more light sources may be configured to generate light source light having a peak wavelength selected from the range of 280-315 nm and / or (b) at least 80%, such as at least about 90% of the spectral power of the light source light of the one or more light sources may be in the 280-315 nm wavelength range, like at least 95%, the light generating system may be configured such that at most 40%, such as at most 30% of the light source light in that wavelength range may be absorbed by the luminescent converter. However, especially, at least about 10% of the light source light in that wavelength range may be absorbed by the luminescent converter.

[0071] Here below, some properties of different types of light source light, when ending up in the first device light, may be provided.

[0072] Table 1 : Properties of different types of UV, violet, and NIR wavelength light

[0073] In further embodiments, the one or more light sources may be configured to generate light source light having a spectral power distribution in the of 280-420 nm wavelength range wherein at least 20% of the spectral power may be within the 400-420 nm wavelength range. Especially, at least 20% of the spectral power may be in the 280-400 nm wavelength range. Hence, in embodiments, at least 20% of the spectral power may be in the <400 nm wavelength range and at least 20% of the spectral power may be in the >400 nm wavelength range. However, other embodiments may also be possible. For instance, in embodiments at least 30% of the spectral power may be in the <400 nm wavelength range and at least 30% of the spectral power may be in the >400 nm wavelength range. Yet, in embodiments at least 35% of the spectral power may be in the <400 nm wavelength range and at least 35% of the spectral power may be in the >400 nm wavelength range. In further specific in embodiments, at least 40 of the spectral power may be in the <400 nm wavelength range and at least 40% of the spectral power may be in the >400 nm wavelength range. Yet, specific in embodiments at least 45 of the spectral power may be in the <400 nm wavelength range and at least 45% of the spectral power may be in the >400 nm wavelength range.

[0074] Yet, in embodiments, at least 20% of the spectral power may be in the 280- 380 nm wavelength range and at least 20% of the spectral power may be in the 400-420 nm wavelength range. However, other embodiments may also be possible. For instance, in embodiments at least 30% of the spectral power may be in the 280-380 nm wavelength range and at least 30% of the spectral power may be in the 400-420 nm wavelength range. Yet, in embodiments at least 35% of the spectral power may be in the 280-380 nm wavelength range and at least 35% of the spectral power may be in the 400-420 nm wavelength range. In further specific embodiments, at least 40 of the spectral power may be in the 280-380 nm wavelength range and at least 40% of the spectral power may be in the 400-420 nm wavelength range. Yet, in specific embodiments at least 45% of the spectral power may be in the 280-380 nm wavelength range and at least 45% of the spectral power may be in the 400- 420 nm wavelength range. This may provide radiation in the long-wavelength range violet light, which may be useful in view of the light absorption properties of the (first) luminescent material in that range.

[0075] Especially, the one or more light sources may comprise a first light source and a second light source (and optionally further light sources). With two or more different light sources, especially solid-state light sources of different bins, it may be possible to provide spectral intensity in different wavelength ranges. Especially, n types of solid-state light sources may provide n peak emission wavelengths. Herein, in embodiments n=l. In other embodiments n=2. These two former types of embodiments are herein described in more detail. However, it is herein not excluded that n>2. As there may be a desire to limit the number of different types, in embodiments n<10, like n<6. However, larger numbers of n are herein not excluded.

[0076] Especially, the first light source may be configured to generate first light source light. Further, especially, the second light source may be configured to generate second light source light. Likewise, the nthlight source may be configured to generate nthlight source light. Note that the first light source, the second light source, etc., may especially be solid-state light sources. Hence, especially the light source light may comprise one or more of the first light source light and the second light source light. Whether or not the lights source light may comprise one or more of the first light source light and the second light source light may depend upon a controlling mode of the light generating system. Especially, however, in embodiments in a controlling mode of the light generating system the light source light may comprise both the first light source light and the second light source light.

[0077] Especially, in embodiments, the first light source light may have a first light source peak emission wavelength (XpSi) and / or the second light source light may have a second light source peak emission wavelength (XpS2). Furthermore, in specific embodiments, |kpsi-kps2|>5 nm, like |XpSi-kps2|>10 nm. More especially, in embodiments |XpSi-kps2|>l 5 nm. In embodiments, |XpSi-kps2|>20 nm, such as |XpSi-kps2|>30 nm. Additionally or alternatively, in embodiments, |XpSi-kps2|<95 nm, like |XpSi-kps2|<85 nm, especially |XpSi-kps2|<75 nm. In specific embodiments, 10 nm < |XpSi-Xps2| < 85 nm.

[0078] Moreover, in embodiments, one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 400-420 nm wavelength range. Moreover, in embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 280-400 nm wavelength range. Alternatively or additionally, in embodiments at least 80%, such as at least about 90% of the spectral power of the one of the first light source light and the second light source light may be in the 400-420 nm wavelength range, like at least 95%, and at least about 90% of the spectral power of the other one of the first light source light and the second light source light may be in the 280-400 nm wavelength range, like at least 95%. Possible advantageous effects can be derived from the above.

[0079] Yet, in embodiments, one of the first light source peak emission wavelength (Xpsi) and the second light source peak emission wavelength (A.pS2) may be selected from the 400-420 nm wavelength range. Moreover, in embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 280-380 nm wavelength range. Alternatively or additionally, in embodiments at least 80%, such as at least about 90% of the spectral power of the one of the first light source light and the second light source light may be in the 400- 420 nm wavelength range, like at least 95%, and at least about 90% of the spectral power of the other one of the first light source light and the second light source light may be in the 280-380 nm wavelength range, like at least 95%. Possible advantageous effects can be derived from the above.

[0080] Further, in embodiments, one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 315-380 nm wavelength range. Further, in embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 280-315 nm wavelength range. Alternatively or additionally, in embodiments at least 80%, such as at least about 90% of the spectral power of the one of the first light source light and the second light source light may be in the 315-380 nm wavelength range, like at least 95%, and at least about 90% of the spectral power of the other one of the first light source light and the second light source light may be in the 280-315 nm wavelength range, like at least 95%. Possible advantageous effects can be derived from the above.

[0081] Further, in embodiments, one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 380-420 nm wavelength range. Further, in embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 280-315 nm wavelength range. Alternatively or additionally, in embodiments at least 80%, such as at least about 90% of the spectral power of the one of the first light source light and the second light source light may be in the 380-420 nm wavelength range, like at least 95%, and at least about 90% of the spectral power of the other one of the first light source light and the second light source light may be in the 280-315 nm wavelength range, like at least 95%. Possible advantageous effects can be derived from the above.

[0082] Yet, in in embodiments, one of the first light source peak emission wavelength (Xpsi) and the second light source peak emission wavelength (A.pS2) may be selected from a primary wavelength range. Further, in embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from a secondary wavelength range. Alternatively or additionally, in embodiments at least 80%, such as at least about 90% of the spectral power of the one of the first light source light and the second light source light may be in the primary wavelength range, like at least 95%, and at least about 90% of the spectral power of the other one of the first light source light and the second light source light may be in the secondary wavelength range, like at least 95%, wherein the primary wavelength range and secondary wavelength range may be (individually) selected from the following wavelength ranges, 400-420 nm, 380-400 nm, 380-420 nm, 280-420 nm, 280-380 nm, 280-315 nm, 315-380 nm, and 330-360 nm, wherein the primary wavelength range and secondary wavelength range differ, and wherein the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2 differ at least 10 nm, such as at least about 15 nm. Possible advantageous effects can be derived from the above. Note that the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2 may in other embodiments also be selected from the same wavelength range of above-mentioned ranges, but still differ at least 5 nm, more especially at least about 10 nm (such as at least about 20 nm).

[0083] A control system may be applied to control the (solid-state) light sources, and may control individual (solid-state) light sources, when there are two or more types of (solid- state) light sources. A control system may also control subsets of (solid-state) light sources, wherein (solid-state) light sources within a subset may be essentially identical (same wavelength bin), whereas (solid-state) light sources from different subsets may be different (from different wavelength bins), wherein each subset may comprise at least a single (solid- state) light source.

[0084] Hence, in embodiments, the control system may be configured to (individually) control the light source light by controlling the first (solid-state) light source and the second (solid-state) light source (and optionally further (solid-state) light sources).

[0085] The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element (determining the behavior or supervising the running of an element), etc., such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc.. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. In embodiments, the control system and element may not be physically coupled. Control can be done via wired and / or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

[0086] The control system may also be configured to receive and execute instructions from a remote control. In embodiments, the control system may be controlled via an App on a device, such as a portable device, like a Smartphone or I-phone, a tablet, etc.. The device is thus not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0087] Hence, in embodiments the control system may (also) be configured to be controlled by an App on a remote device. In such embodiments the control system of the lighting system may be a slave control system or control in a slave mode. For instance, the lighting system may be identifiable with a code, especially a unique code for the respective lighting system. The control system of the lighting system may be configured to be controlled by an external control system which has access to the lighting system on the basis of knowledge (input by a user interface of with an optical sensor (e.g. QR code reader) of the (unique) code. The lighting system may also comprise means for communicating with other systems or devices, such as on the basis of Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0088] The system, or apparatus, or device may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operation mode” or “mode of operation” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and / or after executing the mode one or more other modes may be executed.

[0089] However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. The operation mode may in embodiments also refer to a system, or apparatus, or device, which can only operate in a single operation mode (i.e. “on”, without further tunability).

[0090] Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term “timer” may refer to a clock and / or a predetermined time scheme. In further embodiments, the light generating system may be configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm may be provided by the first luminescent material light, and (ii) in a range of 0-5% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm may be provided by the light source light. Hence, in such embodiments, essentially no light source light may be comprised by the first device light. Further, in such embodiments, at least 95% of the spectral power of the first device light may be provided by the luminescent material light. The relatively low contribution of the spectral power in the visible wavelength range from the light source light may be due to one or more of (i) selecting the one or more light sources such that their intensity is essentially not in the visible, (ii) essentially full conversion by the luminescent converter, and (iii) optically filtering out remaining light source light (transmitted through the luminescent converter).

[0091] However, in other embodiments the light generating system may be configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm may be provided by the first luminescent material light, and (ii) at least 5% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm may be provided by the light source light.

[0092] Further, in embodiments, the luminescent converter may comprise a second luminescent material, different from the first luminescent material. Furthermore, in embodiments, the second luminescent material may be configured to convert at least part of the light source light into second luminescent material light.

[0093] Especially, such second luminescent material may also emit in the red. However, especially such second luminescent material may be a broad-band emitting luminescent material, like having a band width of at least about 40 nm, like at least about 45 nm, or even larger. In embodiments, the second luminescent material may comprise one or more of a divalent europium comprising nitride or and a divalent europium comprising oxynitride (though other luminescent materials may alternatively or additionally also be possible) (see also above). Further, in embodiments the second luminescent material light may have a centroid wavelength ( c2) selected from a wavelength range of 600-660 nm, such as selected from the wavelength range of 610-650 nm. Yet, the second luminescent material light may have a second full width half maximum FWHM2 of at least about 40 nm, like at least about 45 nm, such as at least 50 n, or even in specific embodiments at least about 60 nm. Furthermore, in embodiments, the light generating system may be configured such that (i) at least 60% of a spectral power distribution of the first device light in a wavelength range of 380-780 nm may be provided by the first luminescent material light, (ii) in a range of 0-5% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm may be provided by the light source light, and at least 5% of the spectral power distribution of the first device light in the wavelength range of 380-780 nm may be provided by the second luminescent material light.

[0094] In specific embodiments, the spectral power of the first device light in the 280- 380 nm wavelength range is at maximum 20% of the spectral power of the first device light in the entire 280-780 nm wavelength range, like selected from the range of 0-15%.

[0095] In embodiments, the luminescent converter may be comprised by the first light generating device. Hence, in embodiments the first light generating device may comprise one or more solid-state light sources and the luminescent converter.

[0096] In embodiments, the light generating system may comprise a Chip-on-Board (CoB). The Chip-on-Board may comprise a plurality of the solid-state light sources. As indicated above, the term “CoB” may especially refer to LED chips in the form of a semiconductor chip that is directly mounted onto a substrate. Hence, in embodiments, the CoB may comprise a plurality of the solid-state light sources, wherein first solid-state light sources may especially be LEDs. Further, in embodiments, the Chip-on-Board may comprise the luminescent converter (configured as a coating). The luminescent converter may be configured on top of (and in physical contact with) the plurality of solid-state light sources. Hence, in specific embodiments, the light generating system may comprise a Chip-on-Board, wherein the Chip-on-Board may comprise (i) a plurality of the solid-state light sources, and (ii) the luminescent converter, wherein the luminescent converter may be configured on top of the plurality of solid-state light sources. A light generating system comprising a CoB may be relatively compact, as no separate holder is needed for the first solid-state light sources and / or the luminescent converter. Further, a CoB may be relatively easy to produce.

[0097] In yet other embodiments, the COB may comprise first (solid-state) light sources, second (solid-state) light sources, and optionally further (solid-state) light sources, wherein the types of (solid-state) light sources differ in peak emission wavelengths (with in specific embodiments at least about 5 nm difference, more especially at least about 10 nm). This may allow providing peak emission wavelengths in different wavelength ranges.

[0098] Additionally or alternatively, the light generating system may comprise a LED filament. Hence, the light generating system may comprise (both) a CoB and a LED filament. Alternatively, the light generating system may comprise one of a CoB and a LED filament. LED filaments as such are known, and are e.g. described in US 8,400,051 B2, W02020016058, WO2019197394, etc., which are hereby herein incorporated by reference. In general, a LED filament may in embodiments comprise (i) a plurality of LEDs, arranged on (at least a first major surface of) an elongated carrier, and (ii) an elongated encapsulant covering the plurality of LEDs and at least part of the elongated carrier. The LED filament may in embodiments be defined by a filament length LF, a filament width WF, and a filament thickness TF. Further, the LED filament may have relatively high aspect ratios (LF / WF or LF / TF), such as 10*WF < LF < 900*WF, and 10*TF < LF < 900*TF. In some embodiments, the LED filament may be straight. In other embodiments, the LED filament may be curved. For instance, the filament may have a (2D or 3D) spiraling shape, (like) a helical shape.

[0099] Further, as indicated, the LED filament may comprise an elongated carrier, solid-state light sources, and an encapsulant. Especially, the elongated carrier may support the solid-state light sources. The elongated carrier may e.g. comprise glass, quartz, metal, or sapphire. Further, the elongated carrier may e.g. comprise a polymeric material or (flexible) metal, e.g., a film or foil. The elongated carrier may be rigid (self-supporting), but may (in polymeric embodiments) also be flexible. Further, the elongated carrier may be light transmissive, translucent, or transparent for light, especially visible light. Alternatively, the carrier may be light reflective, especially reflective for one or more of the light source light and the first (and / or second) luminescent material light, such as reflective for at least the light source light and the first (and / or second) luminescent material light. In specific embodiments, the carrier may be diffuse reflective.

[0100] In embodiments, the (elongated) carrier may comprise a first major surface at a first side of the carrier and a second major surface at a second side of the carrier, opposite to the first side. The solid-state light sources may be arranged on at least one of these surfaces. Hence, at least part of, such as all of, the solid-state light sources may be mounted onto the first major surface. Additionally or alternatively, at least part of the solid-state light sources may be mounted onto the second major surface. Hence, the solid-state light sources may be arranged, mounted and / or mechanically coupled on / to the carrier, wherein the carrier may especially be configured to mechanically and / or electrically support the LEDs.

[0101] The LED filament may comprise one or more of LEDs, laser diodes, superluminescent diodes, and multi -junction diodes. Especially, the LED filament may comprise a plurality of LEDs. The (plurality of) solid-state light sources may be arranged in an array (on the elongated carrier). The number of solid-state light sources in the array may be > 4, such as > 8, even more especially > 12, and may e.g. be up to 100, or yet even larger. In embodiments, the number of solid-state light sources in the array may be selected from the range of 10-2000, such as from the range of 10-1500, especially from the range of 10-1000. The solid-state light sources may be configured in a ID (linear) array. Further, the solid-state light sources may be configured in two ID arrays, one on the first major surface of the elongated carrier and one on the second major surface. A 2D array of solid-state light sources of n*m LEDs may also be possible. In embodiments, n may be selected from the range of 1- 4, such as 1-3, like 1-2, such as in embodiments 1 or in embodiments 2, and m may be selected from the range of larger than n, such as especially selected from the range of > 4 (when n<4), like > 6, such as > 8. Hence, a 2D array of solid-state light sources may especially have a (much) smaller number of rows (n) than the number of solid-state light sources in those respective rows (m), such as n / m <0.2, like n / m <0.1, especially n / m <0.05.

[0102] The LED filament may comprise an elongated encapsulant. The encapsulant may (at least partly) enclose the plurality of solid-state light sources. Further, the encapsulant may (at least partly) enclose the elongated carrier, such as at least (part of) one of the first major and second major surface. In general, the encapsulant may be in contact with the elongated carrier and may at least partially enclose all of the solid-state light sources. The encapsulant may be a continuous coating along the filament length LF, at one or both of the first major and the second major surface. Further, the encapsulant may at least partly enclose the solid-state light sources, such as in embodiments at least 50% of the total number of solid-state light sources in the array, such as at least 75%, especially at least 95%, up to 100%.

[0103] The encapsulant may comprise the luminescent converter. Alternatively, the luminescent converter may be an encapsulant, i.e., the luminescent converter may be configured as an encapsulant. Additionally or alternatively, the encapsulant may comprise a light scattering material, configured embedded in an encapsulant material, e.g. a (flexible) polymer material (such as a silicone). In embodiments, the light scattering material may be configured to scatter (or “diffuse”) the light source light and / or the first (and / or second) luminescent material light, especially in a direction transverse to a normal of the (first and / or second) major surface. In specific embodiments, the light scattering material may comprise light scattering particles, such as e.g. at least one of BaSCU, A12O3 and TiCL particles. In embodiments, the LED filament may comprise multiple subfilaments.

[0104] Hence, the light generating system may comprise a LED filament, wherein the LED filament may comprise a plurality of the solid-state light sources arranged on an elongated carrier. Further, the LED filament may comprise an elongated encapsulant configured in physical contact with and covering (such as at least partially enclosing) the plurality of first solid-state light sources and at least part of the elongated carrier. In embodiments, the elongated encapsulant may comprise the luminescent converter. Alternatively, the luminescent converter may be configured as an elongated encapsulant. Hence, in specific embodiments, the light generating system may comprise a LED filament, wherein the LED filament may comprise (i) a plurality of the solid-state light sources arranged on an elongated carrier, and (ii) an elongated encapsulant configured in physical contact with and covering the plurality of solid-state light sources and at least part of the elongated carrier; wherein the elongated encapsulant may comprise the luminescent converter. A light generating system comprising a LED filament may facilitate using the light generating system in decorative light bulbs, as such a light generating system may better resemble a filament of a conventional fluorescent light bulb.

[0105] In embodiments, the LED filament may comprise a single type of solid-state light source (which may be indicated as first solid-state light source). In yet other embodiments, the LED filament may comprise first solid-state light sources, second solid- state light sources, and optionally further solid-state light sources, wherein the types of solid- state light sources differ in peak emission wavelengths (with in specific embodiments at least about 5 nm difference, more especially at least about 10 nm). This may allow providing peak emission wavelengths in different wavelength ranges.

[0106] In embodiments, the light generating system may comprise a LED package. The term “LED package” may refer to a housing comprising a solid-state light source (e.g. a semiconductor chip) and one or more further (optical and / or electrical) components, such as a luminescent converter, a reflector, a lens, a diffuser, electrical connective elements (e.g. wiring), a heat sink, etc.. Especially, the LED package (of the light generating system) may comprise the first light generating device (i.e., the LED package may at least comprise the sone or more solid-state light sources and the luminescent converter). Hence, in specific embodiments, the light generating system may comprises a LED package, wherein the LED package may comprise the first light generating device. A LED package may facilitate providing thermal management for the one or more solid-state light sources. Further, a LED package may facilitate providing one or more of light guiding and beam shaping for the first device light, as well as improving the lifespan of the first light generating device.

[0107] The term “LED package” may in general language usage also be indicated as simply “LED”. That is, in general language usage, the term “LED” may be used to refer to a LED package. In embodiments, a LED package may comprise a solid-state light source (e.g. a semiconductor chip) configured to provide primary radiation, which is used as such, such as e.g. a blue light source, like a blue LED. Such an LED (package), which may not comprise a luminescent material may be indicated as a direct-color LED (dc-LED). Alternatively, the LED package may comprise a solid-state light source configured to provide primary radiation, wherein at least part of the primary radiation is converted into secondary radiation (e.g. by a luminescent material) within the LED package. Such an LED (package) may especially be indicated as a phosphor converted LED or pc-LED. Herein, the LED package (comprising the first light generating device) may be especially based on the conversion of (blue-green) first light source light by a (“KSiF”) first luminescent material. Hence, the invention may especially provide a pc-LED comprising ‘KSiF’ phosphor providing reliable red light.

[0108] In yet other embodiments, the first light generating device of the light package may comprise first solid-state light sources, second solid-state light sources, and optionally further solid-state light sources, wherein the types of solid-state light sources differ in peak emission wavelengths (with in specific embodiments at least about 5 nm, more especially at least about 10 nm). This may allow providing peak emission wavelengths in different wavelength ranges. The solid-state light source(s) of the first light generating device in the light package (comprising in specific embodiments multiple sub-packages) may herein also be indicated as primary solid-state light sources.

[0109] In embodiments, a LED package may further comprise multiple sub-packages, wherein each sub-package may be a LED package as described above. Hence, in embodiments, the light generating system may comprise a LED package comprising the first light generating device and one or more additional light generating devices. Especially, the light generating system may comprise a LED package comprising the first light generating device, a second light generating device, and a third light generating device. In such embodiments, as indicated above, (the first light generating device may be configured to generate first device light, wherein) the first device light may have a first device centroid wavelength ( ca,i) selected from the range of 600-660 nm, such as from the range of 610-650 nm, especially from the range of 620-640 nm.

[0110] The second light generating device may comprise a secondary solid-state light source. The secondary solid-state light source may be selected from the group comprising a light emitting diode (LED), a laser diode, a superluminescent diode, and a (stacked) multijunction light emitting diode, though other options may also be possible (see e.g. above). Further, the secondary solid-state light source may be configured to generate secondary light source light. The secondary light source light may especially have a second peak emission wavelength (Ap2) selected from the range of 360-500 nm, such as from the range of 380-490 nm, especially from the range of 400-470 nm. Hence, the secondary light source light may be one or more of violet light and blue light, such as especially blue light. Further, the second light generating device may comprise a second luminescent converter. The second luminescent converter may be configured as a coating on (top of) the secondary solid-state light source. Further, the second luminescent converter may comprise a third luminescent material. The third luminescent material may be selected from any of the luminescent materials indicated above. In specific embodiments, the third luminescent material may comprise one or more luminescent materials of the type AsBsO Ce, wherein A may comprise one or more of Y, La, Gd, Tb and Lu, and wherein B may comprise one or more of Al, Ga, In and Sc. The third luminescent material may be configured to convert at least part of the secondary light source light received by the third luminescent material into third luminescent material light. Especially, the third luminescent material may be configured to convert > 80%, such as > 90%, especially > 95%, including (essentially) 100%, of (a spectral power of) the secondary light source light received by the third luminescent material into third luminescent material light. The third luminescent material light may have a third centroid wavelength (Zc3). Especially, the third centroid wavelength (Zc3) may be selected from the range of 480-600 nm, such as from the range of 490-590 nm, especially from the range of 500-580 nm. Hence, the third luminescent material light may comprise, such as be, one or more of green light and yellow light (including some blue and orange tones). The term “yellow light” or “yellow emission”, and similar terms, may especially relate to light having a wavelength in the range of about 560-590 nm.

[0111] Further, the second light generating device may be configured to generate second device light. The second device light may comprise the third luminescent material light. Further, in embodiments, the second device light may comprise the secondary light source light. Yet, especially, the second device light may (essentially) consist of the third luminescent material light. The second device light may have a second device centroid wavelength ( ca,2). The second device centroid wavelength ( ca,2) may be selected from the range of 480-600 nm, such as from the range of 490-590 nm, especially from the range of 500-580 nm. That is, the second device light may comprise, such as be, one or more of green light and yellow light (including some blue and orange tones). Hence, in specific embodiments, the secondary solid-state light source may be configured to generate secondary light source light having a second peak wavelength (Xp2) selected from the range of 380-490 nm, and the second light generating device may comprise a second luminescent converter, wherein the second luminescent converter may comprise a third luminescent material; wherein the third luminescent material may be configured to convert at least part of the secondary light source light received by the third luminescent material into third luminescent material light, wherein the third luminescent material light may have a third centroid wavelength (kcs) selected from the range of 490-590 nm; and wherein the second device light may comprise the third luminescent material light. A second light generating device providing yellow and / or green light based on the conversion of blue light by a luminescent material may be more energy efficient than a second light generating device comprising a secondary solid-state light source (directly) providing said yellow and / or green light.

[0112] As indicated above, the LED package may further comprise a third light generating device. The third light generating device may especially comprise a tertiary solid- state light source. The tertiary solid-state light source may be selected from the group comprising a light emitting diode (LED), a laser diode, a superluminescent diode, and a (stacked) multi -junction light emitting diode, though other options may also be possible (see above). Further, the tertiary solid-state light source may be configured to generate tertiary light source light. The tertiary light source light may especially have a third peak emission wavelength (kps) selected from the range of 360-500 nm, such as from the range of 380-490 nm, especially from the range of 420-490 nm. Hence, the tertiary light source light may be one or more of violet light and blue light, such as especially blue light. Further, the third light generating device may be configured to generate third device light. The third device light may comprise the tertiary light source light. In specific embodiments, the third device light may (essentially) consist of the tertiary light source light. In such embodiments, the third light generating device may comprise a light transparent coating, configured on top of (and in physical contact with) a light escape surface of the tertiary solid-state light source. The light transparent coating may in embodiments comprise a light scattering material, wherein the light scattering material may be configured to scatter (or “diffuse”) the tertiary light source light. The light scattering material may comprise light scattering particles, such as e.g. at least one of BaSO4, A12O3 and TiCE particles. Further, the third device light may have a third device centroid wavelength (kca,3). In embodiments, the third device centroid wavelength (kca,3) may be selected from the range of 360-500 nm, such as from the range of 380-490 nm, especially from the range of 420-490 nm. Hence, the third device light may be one or more of violet light and blue light, such as especially blue light. In embodiments, the light generating system (comprising the LED package) may be configured to generate system light. The system light may comprise one or more of the first device light, the second device light, and the third device light. In embodiments, the system light may be colored light, such as selected from the group of blue light, green light, yellow light, orange light, and red light. Especially, the system light may be colored light having a color point selected from the CIE 1931 color space. Alternatively, the system light may be white light.

[0113] The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially between 2700 and 20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700-6500 K. In embodiments, the correlated color temperature (CCT) is especially within about 20 SDCM (standard deviation of color matching) from the BBL (black body locus), such as within 15 SDCM from the BBL, especially within 10 SDCM from the BBL, like within 5 SDCM from the BBL.

[0114] Especially, in a first operational mode of the light generating system (comprising in embodiments the LED package), the system light may be white light. In such embodiments, the system light may especially comprise the first device light, the second device light, and the third device light. Further, the (white) system light (of the first operational mode) may have a correlated color temperature (CCT) selected from the range of > 1300 K, such as from the range of > 1500 K, especially from the range of > 1700 K. Additionally or alternatively, the system light may have a CCT selected from the range of < 8500 K, such as from the range of < 8000 K, especially from the range of < 7500 K. Hence, the system light may have a CCT selected from the range of 1300-8500 K, such as from the range of 1500-8000 K, especially from the range of 1700-7500 K. Further, the system light may have a color rendering index (CRI) of at least 75, such as at least 80, especially at least 85. The system light may have a (CRI) R9 score of > 55, such as > 60, especially > 65. Hence, in specific embodiments, the light generating system may comprise a LED package, wherein the LED package may comprise the first light generating device, a second light generating device, and a third light generating device, wherein: (A) the first device light may have a first device centroid wavelength ( ca,i) selected from the range of 610-660 nm; (B) the second light generating device may comprise a secondary solid-state light source, wherein the second light generating device may be configured to generate second device light having a second device centroid wavelength ( ca,2) selected from the range of 490-590 nm; (C) the third light generating device may comprise a tertiary solid-state light source, wherein the third light generating device may be configured to generate third device light having a third device centroid wavelength ( ca,3) selected from the range of 380-490 nm, more especially 420-490; and (D) in a first operational mode of the light generating system, the light generating system may be configured to generate white system light with a CCT selected from the range of 1500-8000 K. Such a light generating system may especially provide white light suitable for both home (mood) lighting as well as e.g. office lighting. Further, a light generating system comprising a LED package may be relatively compact and energy efficient. Further, in embodiments, the second device light may be green light and the third device light may be blue light.

[0115] In embodiments, the LED package may further comprise a fourth light generating device. The fourth light generating device may especially comprise a quaternary solid-state light source and a fourth luminescent converter. The quaternary solid-state light source may be selected from the group comprising a light emitting diode (LED), a laser diode, a superluminescent diode, and a (stacked) multi -junction light emitting diode, though other options may also be possible (see above). Further, the quaternary solid-state light source may be configured to generate quaternary light source light. The quaternary light source light may especially have a fourth peak emission wavelength (kp- selected from the range of 360-500 nm, such as from the range of 380-490 nm, especially from the range of 400-470 nm. Hence, the quaternary light source light may be one or more of violet light and blue light, such as especially blue light. Further, the fourth luminescent converter may comprise a fourth luminescent material. The fourth luminescent material may comprise one or more luminescent materials selected from the luminescent materials indicated above. In specific embodiments, the fourth luminescent material may comprise a luminescent material of the type AsBsO Ce, wherein A may comprise one or more of Y, La, Gd, Tb and Lu, and wherein B may comprise one or more of Al, Ga, In and Sc. Additionally or alternatively, the fourth luminescent material may comprise one or more luminescent materials of the type M’XM2-2XAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, wherein X comprises a monovalent anion, at least comprising fluorine. Further, the fourth luminescent material may comprise one or more of an oxynitride luminescent material, a nitride luminescent material, a luminescent material of the type MAlSiHvEu2, an SLA-type phosphor, and a SiAlON-type phosphor. Hence, in embodiments, the fourth luminescent material may comprise a primary fourth luminescent material configured to generate one or more of yellow light and green light, and a secondary fourth luminescent material configured to generate one or more of orange light and red light.

[0116] The fourth luminescent material may be configured to convert at least part of the quaternary light source light received by the fourth luminescent material into fourth luminescent material light. Especially, the fourth luminescent material may be configured to convert > 75%, such as > 80%, especially > 85%, like > 90%, of (a spectral power of) the quaternary light source light received by the fourth luminescent material into fourth luminescent material light. Additionally or alternatively, the fourth luminescent material may be configured to convert < 98%, such as < 95%, especially < 90%, of (a spectral power of) the quaternary light source light received by the fourth luminescent material into fourth luminescent material light. The fourth luminescent material light may have a fourth centroid wavelength (Zc4). Especially, the fourth centroid wavelength (Zc4) may be selected from the range of 500-650 nm, such as from the range of 515-630 nm, especially from the range of 530-600 nm. Further, the fourth light generating device may be configured to generate fourth device light. In embodiments, the fourth device light may comprise the fourth luminescent material light. Additionally, the fourth device light may comprise part of the quaternary light source light. Especially, the fourth device light may have a spectral power distribution, wherein > 1%, such as > 2%, especially > 5%, of the spectral power in the wavelength range of 380-780 nm may be provided by the quaternary light source light. Additionally or alternatively, the fourth device light may have a spectral power distribution, wherein < 15%, such as < 12%, especially < 10%, of the spectral power in the wavelength range of 380-780 nm may be provided by the quaternary light source light. The fourth device light may in embodiments be white light. Especially, the fourth device light may be white light having a CCT selected from the range of 1300-8500 K, such as from the range of 1500-8000 K, especially from the range of 1700-7500 K.

[0117] In embodiments, the system light may comprise the fourth device light. Hence, the system light may comprise one or more of (i) red first device light, (ii) yellow (and / or green) second device light, (iii) blue third device light, and (iv) white fourth device light. Especially, the system light may comprise the fourth device light and one or more of the first, second, and third device light, wherein the system light may be white light. Alternatively, the system light may comprise the fourth device light and one or more of the first, second, and third device light, wherein the system light may be colored light. Further, the system light may comprise at least two of the first, second, and third device light (and (essentially) not comprise the fourth device light), wherein the system light may be white light. Alternatively, the system light may comprise one or more of the first, second, and third device light (and (essentially) not comprise the fourth device light), wherein the system light may be colored light.

[0118] In embodiments, the first light generating device, second light generating device, third light generating device, and optional fourth light generating device may be individually controlled (within the LED package). Hence, the light generating system may comprise a control system. The control system may be configured to individually control the first light generating device, the second light generating device, the third light generating device, and the optional fourth light generating device. Especially, the control system may be configured to individually control an intensity of the first device light, the second device light, the third device light, and the optional fourth device light. Hence, the control system may be configured to control the optical properties of the system light. Especially, the control system may be configured to control one or more of a CCT, CRI, CRI R9 (score), color point, and intensity of the system light.

[0119] Hence, in embodiments the light generating system may comprise a Chip-on- Board. Especially, the first light generating device may comprise, such as be, a Chip-on- Board. The Chip-on-Board may comprise a plurality of the solid-state light sources. The solid-state light sources, like LEDs, may be of the same wavelength bin, and may be indicated as first solid-state light sources. Optionally, other type of solid-state light sources may also be comprised by the CoB. Such other solid-state light sources, like LEDs, may be indicated as second solid-state light sources and optionally further type of solid-state light sources. The types of solid-state light sources differ in peak emission wavelengths (with in specific embodiments at least about 5 nm difference, more especially at least about 10 nm). This may allow providing peak emission wavelengths in different wavelength ranges. Hence, the first light generating device may comprise the Chip-on-Board (device). In specific embodiments, the first light generating device may be (configured as) a Chip-on-Board.

[0120] Further, in embodiments the light generating system may comprise a LED filament. Especially, the first light generating device may comprise, such as be, a LED filament. The LED filament may comprise a plurality of the solid-state light sources. The solid-state light sources, like LEDs, may be of the same wavelength bin, and may be indicated as first solid-state light sources. Optionally, other type of solid-state light sources may also be comprised by the LED filament. Such other solid-state light sources, like LEDs, may be indicated as second solid-state light sources and optionally further type of solid-state light sources. The types of solid-state light sources differ in peak emission wavelengths (with in specific embodiments at least about 5 nm difference, more especially at least about 10 nm). This may allow providing peak emission wavelengths in different wavelength ranges. Hence, in embodiments the first light generating device may comprise a LED filament.

[0121] Yet further, in embodiments the light generating system may comprise a LED package. The LED package may comprise a single solid-state light source, like a LED, or optionally a plurality of the solid-state light sources. When a plurality of solid-state light sources ia applied, the solid-state light sources, like LEDs, may be of the same wavelength bin, and may be indicated as first solid-state light sources. Optionally, other type of solid- state light sources may also be comprised by the LED package. Such other solid-state light sources, like LEDs, may be indicated as second solid-state light sources and optionally further type of solid-state light sources. Note that a LED package may comprise subpackages, each comprising one or more solid-state light source. At least one sub-package may comprise the first light generating device. The types of solid-state light sources differ in peak emission wavelengths (with in specific embodiments at least about 5 nm difference, more especially at least about 10 nm). This may allow providing peak emission wavelengths in different wavelength ranges.

[0122] Hence, the LED package may comprise the first light generating device. When the LED package comprises multiple sub-packages, the LED package may comprise the first light generating device and other light generating devices.

[0123] A control system may control the one or more solid-state light sources. Hence, the control system may control the one or more first solid-state light sources, and optionally one or more second solid-state light sources, and yet optionally one or more further solid- state light sources.

[0124] The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems. The terms “visible”, “visible light” or “visible emission” and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. Herein, UV may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm. The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light.

[0125] In yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc... The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system as defined herein. However, the invention may also provide a lighting device selected from the group of a search lighting device, an automotive lighting device, etc., comprising the light generating system as described herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system. For instance, in embodiments the lighting device may comprise a housing or a carrier, configured to house or support one or more of the one or more light sources and the luminescent converter.

[0126] BRIEF DESCRIPTION OF THE DRAWINGS

[0127] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: Figs. 1 A-1B schematically depict some embodiments of the light generating system;

[0128] Fig. 2 shows excitation and emission spectra;

[0129] Fig. 3 schematically depicts an embodiment of the light generating system comprising a LED package;

[0130] Fig. 4 schematically depicts an embodiment of the light generating system comprising a COB;

[0131] Fig. 5 depicts an embodiment of the light generating system comprising a LED filament; and

[0132] Fig. 6 schematically depicts an embodiment of the lighting device.

[0133] The schematic drawings are not necessarily to scale.

[0134] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0135] Figs, la-lb (but also Figs. 3-5) schematically depict embodiments of the light generating system 1000 as described herein. Referring to Figs, la-lb, in specific embodiments, the invention provides a light generating system 1000 comprising a first light generating device 110. The first light generating device 110 may comprise a luminescent converter 2000. Especially, the first light generating device 110 may comprise one or more solid-state light sources 10,20,....

[0136] Moreover, in embodiments, the one or more solid-state light sources 10,20,... may be configured to generate light source light 11,21,... having a peak emission wavelength in a wavelength range of 280-420 nm. Furthermore, in embodiments, the luminescent converter 2000 may be configured in a light receiving relationship with the one or more solid-state light sources 10,20,....

[0137] Further, in embodiments, the luminescent converter 2000 may be configured in the transmissive mode. Especially, the luminescent converter 2000 may comprise a first luminescent material 210. In further embodiments, the first luminescent material 210 may comprise a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese.

[0138] Furthermore, in embodiments, M’ may comprise an alkaline earth cation, M may comprise a monovalent cation, x may be in the range of 0-1, A may comprise a tetravalent cation. In further embodiments, X may comprise a monovalent anion, at least comprising fluorine. Yet, the first luminescent material 210 may be configured to convert at least part of the light source light 11,21,... (received by the first luminescent material 210) into first luminescent material light 211. Note that Fig. la (and Fig. lb) schematically depict a single solid-state light source 10, which may also be indicated as first solid-state light source. Hence, in such embodiments, the phrases light sources 10,20,... or the light source light 11,21,... , and similar phrases, could be read as light source 10 or the light source light 11. However, it is herein not excluded that the first light generating device 110 may not only comprise first solid-state light sources 10, but also second solid-state light sources 20, and optionally further solid-state light sources.

[0139] Reference 500 refers to a LED package. Here, the system 1000 may comprise the LED package 500, wherein the LED package 500 comprises the first light generating device 110 . The LED package 500 may comprise one or more additional (optical) components. In Fig. la, as an example, a LED package 500 comprising a reflective cup 900 is depicted. The system 1000 may further comprise a control system (not depicted in Figs, la-lb).

[0140] In further embodiments, the first light generating device 110 may be configured to generate first device light 111 comprising the first luminescent material light 211. Further, in embodiments, the first device light 111 may be red light.

[0141] Moreover, in embodiments, the first light generating device 110 may be configured such that (i) at least 60% of a spectral power distribution of the first device light 111 in a wavelength range of 380-780 nm may be provided by the first luminescent material light 211 and (ii) in a range of 0-40% of the spectral power distribution of the first device light 111 in the wavelength range of 380-780 nm may be provided by the light source light 11,21,....

[0142] Yet, in embodiments, M may comprise an alkaline cation (especially wherein M may comprise one or more of K and Rb). Further, in embodiments, A may comprise one or more of Si, Ti, Ge, Sn, and Zr. In further embodiments, x=0. Especially, the first luminescent material 210 may comprise (Rb,K)2(Si Ti,Ge)Fe:Mn4+. Hence, the luminescent material may comprise one or more of Rb and K, and one or more of Si, Ti, and Ge.

[0143] In further embodiments, the one or more solid-state light sources 10,20,... may be configured to generate light source light 11,21,... having a peak wavelength selected from the range of 400-420 nm. Alternatively or additionally, in embodiments, the one or more solid-state light sources 10,20,... may be configured to generate light source light 11,21,... having a peak wavelength selected from the range of 380-400 nm. Alternatively or additionally, the one or more solid-state light sources 10,20,... may in embodiments be configured to generate light source light 11,21,... having a peak wavelength selected from the range of 280-315 nm. Alternatively or additionally, the one or more solid-state light sources 10,20,... may be configured to generate light source light 11,21,... having a peak wavelength selected from the range of 330-360 nm.

[0144] The indication “10,20,...” indicates that first solid-state light sources 10 and / or second solid-state light sources 20, and / or further light sources may be available; thus including only first solid-state light sources 10, or only second solid-state light sources 20, etc. The indication “11,21,...” indicates that first light source light 11 and / or second light source light 21, and / or further light source light may be available; thus including only first light source light 11, or only second light source light 21, etc. Of course, first light source light 11 may be generated by (only) the first solid-state light source 10, second light source light 21 may be generated by (only) the second solid-state light source 20, etc.

[0145] Herein, in the detailed description, mainly embodiments are described wherein the first light generating device 110 comprises a single type of light source, indicated as first solid-state light sources 10. In other embodiments, second and further light sources are described in relation to other light generating devices, except for the embodiment of Fig. 4.

[0146] In further embodiments, the one or more solid-state light sources 10,20,... may be configured to generate light source light 11,21,... having a spectral power distribution in the of 280-420 nm wavelength range wherein at least 20% of the spectral power may be within the 400-420 nm wavelength range. Especially, at least 20% of the spectral power may be in the 280-400 nm wavelength range.

[0147] Though essentially only depicted in the embodiment of Fig. 4, the below about first solid-state light sources 10 and second solid-state light sources 20, may also apply to the embodiments of Figs, la-lb and 5.

[0148] Hence, with reference to Fig. 4 (but not limiting to the embodiment schematically depicted in Fig. 4), in embodiments, the one or more solid-state light sources 10,20,... may comprise a first solid-state light source 10 and a second solid-state light source 20 (and optionally further light sources). Especially, the first solid-state light source 10 may be configured to generate first light source light 11. Moreover, in embodiments, the second solid-state light source 20 may be configured to generate second light source light 21 (wherein the light source light 11,21,... may comprise one or more of the first light source light 11 and the second light source light 21). Especially, the first light source light 11 may have a first light source peak emission wavelength (XpSi). Further, in embodiments, the second light source light 21 may have a second light source peak emission wavelength (XpS2). Further, in embodiments, |XpSi-kps2|>l 0 nm. Further, in embodiments, one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (XpS2) may be selected from the 400-420 nm wavelength range. Furthermore, in embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 280-400 nm wavelength range.

[0149] Furthermore, in embodiments, one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (XpS2) may be selected from the 315-380 nm wavelength range. In further embodiments, the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) may be selected from the 280-315 nm wavelength range.

[0150] Further, in embodiments, the control system 300 may be configured to control the light source light 11,21,... by controlling the first solid-state light source 10 and the second solid-state light source 20 (and optionally further light sources).

[0151] Further, in embodiments, the light generating system 1000 may be configured such that (i) at least 60% of a spectral power distribution of the first device light 111 in a wavelength range of 380-780 nm may be provided by the first luminescent material light 211, and (ii) in a range of 0-5% of the spectral power distribution of the first device light 111 in the wavelength range of 380-780 nm may be provided by the light source light 11,21,....

[0152] Referring to Fig. lb, in further embodiments, the luminescent converter 2000 may comprise a second luminescent material 220, different from the first luminescent material 210. Moreover, in embodiments, the second luminescent material 220 may be configured to convert at least part of the light source light 11,21,... (received by the second luminescent material 220) into second luminescent material light 221. Furthermore, in embodiments, the light generating system 1000 may be configured such that (i) at least 60% of a spectral power distribution of the first device light 111 in a wavelength range of 380-780 nm may be provided by the first luminescent material light 211, (ii) in a range of 0-5% of the spectral power distribution of the first device light 111 in the wavelength range of 380-780 nm may be provided by the light source light 11,21,..., and (iii) at least 5% of the spectral power distribution of the first device light 111 in the wavelength range of 380-780 nm may be provided by the second luminescent material light 221. Moreover, in embodiments, the second luminescent material 220 may comprise one or more of a divalent europium comprising nitride or and a divalent europium comprising oxynitride. Note that the second luminescent material 220 is herein amongst others described in relation to the embodiments of Fig. lb, but may equally well apply to the embodiments schematically depicted in Figs. 3, 4 and 5.

[0153] Fig. 2 shows some excitation and emission spectra of tetravalent manganese based luminescent materials. By way of example, the first luminescent material 210 may comprise a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein A may comprise (at least) Ti. The absorption / excitation spectrum of such a first luminescent material 210 is indicated by reference 212a, and the corresponding first luminescent material light 211 is indicated by reference 211a. Further, the first luminescent material 210 may comprise a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein A may comprise (at least) Si. Reference 212b indicates the absorption / excitation spectrum of such a first luminescent material 210, and reference 211b indicates the corresponding first luminescent material light. Additionally or alternatively, the first luminescent material 210 may comprise a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein A may comprise (at least) Ge. Reference 212c indicates the absorption / excitation spectrum of a first luminescent material 210 wherein A comprises (at least) Ge and Si (with corresponding first luminescent material light 211c), and reference 212d indicates the absorption / excitation spectrum of a first luminescent material 210 wherein A comprises (at least) Ge (with corresponding first luminescent material light 21 Id). The first luminescent material 210 may comprise (K,Rb)2(Si,Ti)Fe:Mn4+, such as especially K2(Si,Ti)Fe:Mn4+. Further, the first luminescent material 210 may comprise K2(Sii- xTix)Fe:Mn4+, wherein x may be selected from the range of > 0.6. However, other embodiments may also be possible.

[0154] Referring to Fig. 2, the (first) luminescent material of the type M’xM2-2xAX6 provides multiple narrow emission bands (“lines”) in (amongst others) the red wavelength range. Essentially each of these bands has a full width half maximum well below 50 nm, such as below 20 nm. Of course, such narrow bands may (partly) merge into broader bands. However, it is also noted that the width of the narrow bands in the emission spectra may also (partly) be due to the spectral resolution of the measurement setup. Hence, the first luminescent material light 211 may have a first centroid wavelength (Xcl) selected from the wavelength range of 610-650 nm, and may comprise one or more emission bands having a first full width half maximum (FWHM1) of at maximum 50 nm.

[0155] Fig. 3 schematically depicts an embodiment of the light generating system 1000 comprising a LED package 500. The LED package 500 may comprise the first light generating device 110, a second light generating device 120, and a third light generating device 130. The first device light 111 (of the first light generating device 110) may have a first device centroid wavelength ( ca,i) selected from the range of 620-640 nm. Further, the second light generating device 120 may comprise a secondary solid-state light source 20. The second light generating device 120 may especially be configured to generate second device light 121 having a second device centroid wavelength ( ca,2) selected from the range of 490- 590 nm. Further, the third light generating device 130 may comprise a tertiary solid-state light source 30. Additionally, the third light generating device 130 may be configured to generate third device light 131 having a third device centroid wavelength ( ca,s) selected from the range of 380-490 nm. In a first operational mode of the light generating system 1000, the light generating system 1000 may be configured to generate system light 1001 comprising the first device light 111, the second device light 121, and the third device light 131. Especially, (in the first operational mode,) the system light 1001 may be white light with a CCT selected from the range of 1500-8000 K (and a color rendering index of at least 80). The secondary solid-state light source 20 may be configured to generate secondary light source light 21 having a second peak wavelength (Xp2) selected from the range of 380-490 nm. Further, the second light generating device 120 may comprise a second luminescent converter 2200. The second luminescent converter 2200 may comprise a third luminescent material 230. The third luminescent material 230 may especially be configured to convert at least part of the secondary light source light 21 received by the third luminescent material 230 into third luminescent material light 231. The third luminescent material light 231 may have a third centroid wavelength (kcs) selected from the range of 490-590 nm. Further, the second device light 121 may comprise the third luminescent material light 231.

[0156] Hence, the invention also provides embodiments of the light generating system 1000 comprising a LED package 500, which may comprise a plurality of sub-packages. Moreover, in embodiments, the LED package 500 may comprise the first light generating device 110, a second light generating device 120, and a third light generating device 130. Especially, the first device light 111 may have a first device centroid wavelength ( ca,i) selected from the range of 610-660 nm (in the wavelength range of 380-780 nm). In further embodiments, the second light generating device 120 may be configured to generate second device light 121 having a second device centroid wavelength ( ca,2) selected from the range of 490-590 nm. In further embodiments, the third light generating device 130 may be configured to generate third device light 131 having a third device centroid wavelength ( ca,s) selected from the range of 420-490 nm. In further embodiments, in a first operational mode of the light generating system 1000, the light generating system 1000 may be configured to generate white system light 1001 with a CCT selected from the range of 1500-8000 K (and a color rendering index of at least 80) and comprising the first device light 111, the second device light 121, and the third device light 131. Moreover, in embodiments, the second light generating device 120 may comprise a second luminescent converter 2200. Further, in embodiments, the secondary solid state solid-state light source 20 may be configured to generate secondary light source light 21 having a second peak wavelength (Xp2) selected from the range of 380-490 nm. Especially, the second luminescent converter 2200 may comprise a third luminescent material 230. Especially, the third luminescent material 230 may be configured to convert at least part of the secondary light source light 21 received by the third luminescent material 230 into third luminescent material light 231. Furthermore, in embodiments, the third luminescent material light 231 may have a third centroid wavelength (kcs) selected from the range of 490-590 nm. Moreover, in embodiments, the second device light 121 may comprise the third luminescent material light 231.

[0157] Further, the LED package 500 may further comprise a fourth light generating device 140. The fourth light generating device 140 may comprise a quaternary solid-state light source 40. The quaternary solid-state light source 40 may be configured to generate quaternary light source light 41 having a fourth peak wavelength (kp-t) selected from the range of 380-490 nm. Further, the fourth light generating device 140 may comprise a fourth luminescent converter 2400. The fourth luminescent converter 2400 may comprise a fourth luminescent material 240. The fourth luminescent material 240 may especially be configured to convert at least part of the quaternary light source light 41 received by the fourth luminescent material 240 into fourth luminescent material light 241. The fourth light generating device 140 may be configured to generate fourth device light 141 comprising the fourth luminescent material light 241 and at least part of the quaternary light source light 41. In embodiments, the fourth device light 141 may be white light. For clarity, the first, second, third, and fourth solid-state light sources 10,20,30,40 are indicated with dashed lines in Fig. 3. The light generating system 1000 may comprise a control system 300. The control system 300 may especially be configured to individually control the first light generating device 110, the second light generating device 120, the third light generating device 130, and the fourth light generating device 140.

[0158] Referring to Fig. 4, in further embodiments, the light generating system 1000 may comprise a Chip-on-Board (CoB) 600. Moreover, in embodiments, the Chip-on-Board (CoB) 600 may comprise (i) a plurality of the first solid-state light source 10, and (ii) the luminescent converter 2000. Further, in embodiments, the luminescent converter 2000 may be configured on top of the plurality of first solid state solid-state light sources 10. Especially, the light generating system 1000 may comprise a LED filament 400 (see Fig. 5). Further, in embodiments, the LED filament 400 may comprise (i) a plurality of the first solid- state light source 10 arranged on an elongated carrier 5, and (ii) an elongated encapsulant 410 configured in physical contact with and covering the plurality of first solid state solid-state light sources 10 and at least part of the elongated carrier 5. Furthermore, in embodiments, the elongated encapsulant 410 may comprise the luminescent converter 2000.

[0159] Fig. 5 schematically depicts an embodiment of the light generating system 1000 comprising one or more (first) solid state solid-state light sources 10. Further, each of the one or more solid-state light sources 10 may be configured to generate light source light 11 as indicated above. Further, Fig. 5 schematically depicts an embodiment of the light generating system 1000 comprising a LED filament 400. The LED filament 400 may comprise (i) a plurality of the first solid state solid-state light source 10 (and optionally a plurality of the second solid state solid-state light source 20) arranged on an elongated carrier 5, and (ii) an elongated encapsulant 410 configured in physical contact with and at least partially enclosing the plurality of first solid state solid-state light sources 10 (and the optional plurality of second solid-state light sources 20) and at least part of the elongated carrier 5. The elongated encapsulant 410 may comprise the luminescent converter 2000.

[0160] Fig. 6 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig. 6 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, Fig. 6 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001, and may in specific embodiments thus be system light 1001. Reference 1300 refers to a space, such as a room. Reference 1305 refers to a floor and reference 1310 to a ceiling; reference 1307 refers to a wall. Fig. 6 also schematically depicts an embodiments of an outdoor light, or stage light, or stadium light. Fig. 6 also schematically depicts a vehicle, like an automobile, but this may also be a truck, a motor cycle, etc. etc., with automotive lighting 4, e.g. headlights. These automotive lighting 4 may also comprise the lighting device 1200.

[0161] The term “plurality” refers to two or more. The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’. The term “and / or” especially relates to one or more of the items mentioned before and after “and / or”. For instance, a phrase “item 1 and / or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species". Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0162] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0163] The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

[0164] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0165] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. In yet a further aspect, the invention (thus) provides a software product, which, when running on a computer is capable of bringing about (one or more embodiments of) the method as described herein. The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system. The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and / or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and / or shown in the attached drawings.

[0166] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

1. CLAIMS:

1. A light generating system (1000) comprising a first light generating device(110), wherein the first light generating device (110) comprises one or more solid-state light sources (10,20,..) and a luminescent converter (2000), wherein: the one or more solid-state light sources (10,20,..) are configured to generate light source light (11,21,..) having a peak emission wavelength in a wavelength range of 280- 420 nm; the luminescent converter (2000) is configured in a light receiving relationship with the one or more solid-state light sources (10,20,..); wherein the luminescent converter (2000) comprises a first luminescent material (210); wherein the first luminescent material(210) is a luminescent material of the type M’xM2-2xAX6 doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an monovalent cation, x is in the range of 0-1, A comprises a tetravalent cation, and wherein X comprises a monovalent anion, at least comprising fluorine; wherein the first luminescent material (210) is configured to convert at least part of the light source light (11,21,..) into first luminescent material light(211), wherein the first luminescent material light (211) has a first centroid wavelength (kcl) selected from the range of 610-650 nm and having a first full width at half maximum FWHM1 of < 50 nm; and the first light generating device (110) is configured to generate first device light (111) comprising the first luminescent material light (211); wherein the first device light(111) is red light; wherein the first light generating device (110) is configured such that (i) at least 95% of a spectral power distribution of the first device light (111) in a wavelength range of 380-780 nm is in the wavelength range of 590-780 nm, and at least 60% of the spectral power distribution of the first device light (111) in a wavelength range of 380-780 nm is provided by the first luminescent material light (211); and (ii) in a range of 0-5% of the spectral power distribution of the first device light (111) in the wavelength range of 380-780 nm is provided by the light source light (11,21,..).

2. The light generating system (1000) according to claim 1, wherein M comprises potassium, wherein x is 0, and wherein A comprises germanium.

3. The light generating system (1000) according to any one of the preceding claims, wherein the one or more solid-state light sources (10,20,..) are configured to generate light source light (11,21,..) having a peak wavelength selected from the range of 380-400 nm.

4. The light generating system (1000) according to any one of the preceding claims, wherein the one or more solid-state light sources (10,20,..) are configured to generate light source light (11,21,..) having a peak wavelength selected from the range of 280-315 nm.

5. The light generating system (1000) according to any one of the preceding claims, wherein the one or more solid-state light sources (10,20,..) are configured to generate light source light (11,21,..) having a peak wavelength selected from the range of 330-360 nm.

6. The light generating system (1000) according to any one of the preceding claims, wherein the one or more solid-state light sources (10,20,..) are configured to generate light source light (11,21,..) having a spectral power distribution in the of 280-420 nm wavelength range wherein at least 30% of the spectral power is within the 400-420 nm wavelength range, and wherein at least 30% of the spectral power is in the 280-380 nm wavelength range.

7. The light generating system (1000) according to any one of the preceding claims, wherein the one or more solid-state light sources (10,20,..) comprise a first light source (10) and a second light source (20), wherein the first light source (10) is configured to generate first light source light (11), wherein the second light source (20) is configured to generate second light source light (21) comprises one or more of the first light source light (11) and the second light source light (21)], wherein the first light source light (11) has a first light source peak emission wavelength (XpSi), wherein the second light source light (21) has a second light source peak emission wavelength (XpS2), and wherein |XpSi-kps2|>30 nm.

8. The light generating system (1000) according to claim 7, wherein one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) is selected from the 400-420 nm wavelength range, and wherein the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (XpS2) is selected from the 280-380 nm wavelength range.

9. The light generating system (1000) according to claim 7, wherein one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) is selected from the 315-380 nm wavelength range, and wherein the other one of the first light source peak emission wavelength (XpSi) and the second light source peak emission wavelength (A.pS2) is selected from the 280-315 nm wavelength range.

10. The light generating system (1000) according to any one of claims 7-9, further comprising a control system (300), wherein the control system (300) is configured to control the light source light (11,21,..) by controlling the first light source (10) and the second light source (20).

11. The light generating system (1000) according to any one of the preceding claims, wherein the light generating system (1000) is configured such that in a range of 0-5% of the spectral power distribution of the first device light (111) in the wavelength range of 380-780 nm is provided by the light source light (11,21,..); and wherein the luminescent converter (2000) is configured in the transmissive mode.

12. The light generating system (1000) according to any one of the preceding claims, wherein the luminescent converter (2000) comprises a second luminescent material (220), different from the first luminescent material (210), wherein the second luminescent material (220) is configured to convert at least part of the light source light (11,21,..) into second luminescent material light (221) having a centroid wavelength ( c2) selected from a wavelength range of 600-660 nm, wherein the light generating system (1000) is configured such that in a range of 0-5% of the spectral power distribution of the first device light (111) in the wavelength range of 380-780 nm is provided by the light source light (11,21,..), and at least 20% of the spectral power distribution of the first device light (111) in the wavelength range of 380-780 nm is provided by the second luminescent material light (221).

13. The light generating system (1000) according to any one of the preceding claims 1-12, wherein the light generating system (1000) comprises a LED package (500), wherein the LED package (500) comprises the first light generating device (110), a second light generating device (120), and a third light generating device (130), wherein:the first device light (111) has a first device centroid wavelength ( ca,i) selected from the range of 610-660 nm; the second light generating device (120) is configured to generate second device light (121) having a second device centroid wavelength ( ca,2) selected from the range of 490-590 nm, and wherein the second device light is green light; the third light generating device (130) is configured to generate third device light (131) having a third device centroid wavelength ( ca,s) selected from the range of 420- 490 nm, and wherein the third device light is blue light; and in a first operational mode of the light generating system (1000), the light generating system (1000) is configured to generate white system light (1001) with a CCT selected from the range of 1500-8000 K and a color rendering index of at least 80 and comprising the first device light (111), the second device light (121), and the third device light (131).

14. The light generating system (1000) according to any one of the preceding claims 1-12, wherein one of the following applies: the light generating system (1000) comprises a Chip-on-Board (CoB) (600), wherein the Chip-on-Board (CoB) (600) comprises (i) a plurality of solid-state light sources (10), and (ii) the luminescent converter (2000), wherein the luminescent converter (2000) is configured on top of the plurality of solid-state light sources (10); and the light generating system (1000) comprises a LED filament (400), wherein the LED filament (400) comprises (i) a plurality of the solid-state light sources (10) arranged on an elongated carrier (5), and (ii) an elongated encapsulant (410) configured in physical contact with and covering the plurality of first solid-state light sources (10) and at least part of the elongated carrier (5); wherein the elongated encapsulant (410) comprises the luminescent converter (2000).

15. A lighting device (1200) selected from the group of a lamp (1), a luminaire (2), a search lighting device, an automotive lighting device, comprising the light generating system (1000) according to any one of the preceding claims.

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