A light emitting device

Abstract

A light emitting device (1) configured to, in operation, emit device light (2) from a light exit surface (22), the light emitting device comprising: a solid-state light source (3) configured to, in operation, emit first solid-state light source light (4) and comprising a light output surface (31) with an edge (32), an edge axis (EA), and a central axis (CA); a first luminescent element (5) arranged to cover the solid-state light source (3) and comprising a first major surface (52) and a second major surface (53), the first luminescent element (5) comprising a narrow-band red luminescent material (51), the first luminescent element (5) being configured to convert at least part of the first solid-state light source light (4) into first converted light (6); and a reflecting element (7) covering a second part (532) of the second major surface (53) being different from the first part (531), a transition (533) being formed between the first part (531) and the second part (532). The edge (32) is arranged with a first shortest distance (d1) to the central axis (CA) being smaller than or equal to a second shortest distance (d2) with which the transition (533) is arranged to the central axis (CA). The reflecting element (7) is aligned with the at least one first solid-state light source (3) such that an angle, θ, between (i) a main emission direction of the first solid-state light source light (4) being perpendicular to the light output surface (31) and coinciding with the edge axis (EA) and (ii) a direction of emission of the first solid-state light source light (4) emerging from the edge (32) and intersecting with the transition (533) fulfills 45° ≥ θ ≥ 0°. The reflecting element (7) comprises a surface area, A1, facing the second major surface (53), the light output surface (31) of the at least one first solid-state light source (3) comprises a surface area A2, and A1 ≥ A2.

Description

[0001] 2024PF80378

[0002] A light emitting device

[0003] FIELD OF THE INVENTION

[0004] The invention relates to a light emitting device configured to, in operation, emit device light, the light emitting device comprising at least one solid-state light source configured to, in operation, emit solid-state light source light having a first peak emission wavelength, XI, and a first luminescent element arranged such as to cover the at least one solid state light source, the first luminescent element comprising a narrow-band red luminescent material and a narrow-band green luminescent material. The invention further relates to a lamp and a luminaire comprising such a light emitting device.

[0005] As used herein, the term “blue light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 420 nm to 500 nm.

[0006] As used herein, the term “green light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 520 nm to 570 nm.

[0007] As used herein, the term “yellow light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 575 nm to 594 nm.

[0008] As used herein, the term “red light” is intended to refer to light with a peak wavelength falling within the wavelength interval of 620 nm to 750 nm.

[0009] As used herein, the term “solid state light source” is intended to refer to any solid state light source, including LEDs as well as diode lasers, super-luminescent diodes, and multi -junction diodes, comprising one or more LEDs.

[0010] BACKGROUND OF THE INVENTION

[0011] The Mn4+-activated fluoride phosphor, typically K2SiF6:Mn4+, has become a renowned red-emitting phosphor for white light emitting diodes (LEDs) due to its narrow emission band, optimal peak wavelength, high efficiency, and a favorable excitation spectrum. First major dominant LED manufacturers such as BRIDGELUX are now also using KSiF phosphor for red light emitting LEDs.

[0012] In order to make high quality / pure red light, a narrow emission band is needed, e.g., meeting HUE requirements. 2024PF80378

[0013] 2

[0014] However, fluoride phosphors exhibit a relatively poor absorption of blue light. Therefore, there is a desire to provide a light emitting device with which the path length of blue LED light emitted by a blue LED light source in a wavelength converter comprising KSiF phosphor can be increased.

[0015] SUMMARY OF THE INVENTION

[0016] It is an object of the present invention to overcome this problem, and to provide a light emitting device with which the path length of blue solid-state light source light emitted by a blue solid-state light source covered by a luminescent element comprising KSiF phosphor can be increased, and with which the absorption of blue light in fluoride phosphors, such as KSiF phosphors, may be increased.

[0017] According to a first aspect of the invention, this and other objects are achieved by means of light emitting device configured to, in operation, emit device light from a light exit surface, the light emitting device comprising at least one first solid-state light source configured to, in operation, emit first solid-state light source light having a first peak emission wavelength, XI, within a wavelength range of 400 nm to 490 nm, the at least one first solid-state light source comprising a light output surface with an edge, an edge axis, EA, extending perpendicular to the light output surface, and a central axis, CA, extending perpendicular to the light output surface, a first luminescent element arranged to cover (or at least partly enclose) the at least one first solid state light source, the first luminescent element comprising a first major surface and a second major surface opposite to the first major surface, the light exit surface forming a first part of the second major surface, the first luminescent element comprising a narrow-band red luminescent material, the first luminescent element being configured to receive the first solid-state light source light and convert at least part of the first solid-state light source light into first converted light having a second peak emission wavelength, X2, within a wavelength range of 610 nm to 650 nm and having a full-width-half-maximum, FWHM, being smaller than or equal to 60 nm, and a reflecting element, wherein the reflecting element covers a second part of the second major surface of the first luminescent element, the second part being different from the first part, and wherein a transition is formed between the first part and the second part, wherein the edge is arranged with a first shortest distance, dl, to the central axis, CA, wherein the transition is arranged with a second shortest distance, d2, to the central axis, CA, and wherein the first shortest distance, dl, is smaller than or equal to the second shortest distance, d2, wherein the reflecting element is aligned with the at least one first solid-state light source 2024PF80378

[0018] 3 such that an angle, 0, between (i) a main emission direction of the first solid-state light source light being perpendicular to the light output surface and coinciding with the edge axis, EA, and (ii) a direction of emission of the first solid-state light source light emerging from the edge and intersecting with the transition fulfills 45° > 0 > 0°, and wherein the reflecting element comprises a surface area, Al, facing the second major surface, wherein the light output surface of the at least one first solid-state light source comprises a surface area A2, and wherein Al > A2.

[0019] Thereby, a light emitting device with which the path length of blue solid-state light source light emitted by a blue solid-state light source in a luminescent element comprising a narrow-band red luminescent material such as KSiF phosphor can be increased, and with which the absorption of blue light in the narrow-band red luminescent material, such as KSiF phosphor, may be increased is provided for. Such a light emitting device further comprises a high efficiency.

[0020] The angle Q may fulfill the relation 25° > Q > 0°.

[0021] Thereby, an improved efficiency is obtained. The reason is that converted light can better escape past the reflecting element.

[0022] The angle Q may fulfill the relation 45° > 0 > 25°.

[0023] Thereby, a further improved light conversion is obtained, because of the relatively large surface area of the reflecting element.

[0024] The following may apply: (i) the first part is in a range of 60 % to 90 % of the second major surface, and (ii) the second part is in a range of 10 % to 40 % of the second major surface.

[0025] In this way it is ensured that the light exit window forms a major part of the second major surface, providing sufficient area for light exiting, and reducing light loss due to light trapping, e.g., due to multiple reflections. Thereby, a further improved efficiency is obtained.

[0026] The following may apply: (i) the first luminescent element has a thickness in a range from 0.2 mm to 0.7 mm, (ii) the first luminescent element has a width and a length in a range from 1 mm to 3 mm, and (iii) the first solid-state light source has a with and a length in a range from 0.1 mm to 1 mm.

[0027] It has been shown that a first luminescent element and a first solid-state light source having these dimensions works best.

[0028] The reflecting element may be diffuse reflective and may comprise a reflectivity of at least 80 %. 2024PF80378

[0029] 4

[0030] Thereby, a high efficiency is obtained. The reason is that when light is reflected a part may be lost due to absorption. Especially in case of multiple reflections.

[0031] The narrow-band red luminescent material may comprise a phosphor 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, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. Relevant alkaline cations (M) are sodium (Na), potassium (K) and rubidium (Rb). Optionally, also lithium and / or cesium may be applied. 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’xNfc- 2xAXe, 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’xM2-2xAXe luminescent material has the hexagonal phase. In yet another embodiment, the M’xM2-2xAX6 luminescent material has the cubic phase. For x=0, the composition is NfcxAXe. Relevant alkaline earth cations (M’) are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba.

[0032] The narrow-band red luminescent material may alternatively or additionally 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, wherein y + z < 1.

[0033] The narrow-band red luminescent material may alternatively or additionally comprise quantum dots and / or organic dyes.

[0034] At least 70 w / w% (i.e. weight percent) or at least 80 w / w% of the luminescent material in the first luminescent element is the phosphor 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 tetraval ent cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine.

[0035] This type of phosphor provides high efficiency and high purity red light due to its advantageous peak emission wavelength position and its very narrow FWHM. However, this type of phosphor also shows very poor light absorption and cannot be excited well. Therefore, this invention is particularly well suited for this type of phosphor. 2024PF80378

[0036] 5

[0037] The at least one first solid-state light source and the first luminescent element may be arranged (e.g. partially enclosed) in a reflective cup, the reflective cup being configured to direct the first converted light towards the light exit surface.

[0038] Thereby, loss of light originating from the first solid-state light source which would otherwise escape from the light emitting device through other surfaces than the light exit surface is avoided or reduced considerably.

[0039] The light emitting device may further comprise one or more further solid state light sources, wherein the one or more further solid state light sources comprises one or more of the following:

[0040] At least one second solid-state light source configured to, in operation, emit second solid-state light source light, the at least one second solid-state light source being covered by a second luminescent element, the second luminescent element comprising a green luminescent material, the second luminescent element being configured to receive the second solid-state light source light and convert the second solid-state light source light into second converted light having a third peak emission wavelength, X3, within a wavelength range of 500 nm to 570 nm, the second solid-state light source light being green light.

[0041] At least one third solid-state light source configured to, in operation, emit third solid-state light source light having a fourth peak emission wavelength, X4, within a wavelength interval of 420 nm to 490 nm, the third solid-state light source light being blue light.

[0042] At least one fourth solid-state light source configured to, in operation, emit fourth solid-state light source light, the at least one fourth solid-state light source being covered by a third luminescent element, the third luminescent element comprising a greenyellow luminescent material and a red luminescent material, the third luminescent element being configured to receive the fourth solid-state light source light and convert the fourth solid-state light source light into third converted light having a fifth peak emission wavelength, X5, falling within the wavelength interval of 500 nm to 660 nm, the fourth solid- state light source light being white light having a correlated color temperature in a range from 2000K to 6500K (or in a range from 2000K to 3500K) and e.g. a color rendering index of at least 80 or at least 85.

[0043] Thereby, a light emitting device is provided with which white device light of a high quality may be provided and which comprises a high efficiency.

[0044] One or more of the following may apply: the third solid-state light source is free from a reflecting element arranged on a part of a major surface of the second 2024PF80378

[0045] 6 luminescent element forming a part of the light exit surface, and the fourth solid-state light source is free from a reflecting element arranged on a part of a major surface of the third luminescent element forming a part of the light exit surface. In other words, the third and / or the fourth solid-state light source may be free from a reflecting element of the type covering the first solid state light source.

[0046] Thereby, the quality and brightness of the device light provided for is improved further.

[0047] The one or more of the further solid state light sources may be arranged in a respective reflective cup configured to direct the second converted light, the third solid-state light source light and the third converted light, respectively, towards the light exit surface.

[0048] Thereby, loss of light originating from the one or more further solid-state light sources which would otherwise escape from the light emitting device through other surfaces than the light exit surface is avoided or reduced considerably.

[0049] The at least one third solid-state light source may be covered by a transparent material.

[0050] Thereby, the at least one third solid-state light source is protected from external influences.

[0051] The at least one third solid-state light source may be uncovered.

[0052] Thereby a light emitting device with a simpler construction is provided for.

[0053] The at least one first solid-state light source and, where provided, the one or more further solid state light sources may form part of a LED package.

[0054] Thereby, a more compact light emitting device is provided for.

[0055] The light emitting device may further comprise a controller configured to individually control the at least one first solid-state light source and, where provided, the one or more further solid state light sources to vary one or more of the correlated color temperature, CCT, and the color point of the device light.

[0056] Thereby, a light emitting device with an improved efficiency and adaptability to requirements of various applications is provided for.

[0057] The device light may be light having a correlated color temperature, CCT, in the range 2000 K - 6500 K and a color rendering index, CRI, of at least 80.

[0058] The device light may be red light or reddish light or magenta light. The first solid-state light source light may be red or reddish or magenta light. 2024PF80378

[0059] 7

[0060] The reflecting element may comprise a surface area being between 5 % and 50 % larger than a surface area of a light emitting surface the at least one first solid state light source.

[0061] The reflecting element may have a size being from 5 % to 30 %, or from 5 % to 50 % larger than the first solid-state light source on all sides.

[0062] Thereby, a larger path length is obtained while still allowing sufficient converted light to escape past the reflective element. Thereby a higher efficiency is obtained.

[0063] The surface area, Al, of the reflecting element may be between 50 % and 100 % larger than a surface area, A2, of the light emitting surface of the at least one first solid state light source.

[0064] Thereby, a further improved light conversion and / or a shallower light emitting device is obtained.

[0065] The reflecting element may be diffuse reflective. Alternatively, or additionally, the reflecting element may comprise a reflectivity of at least 80 %.

[0066] Thereby a higher efficiency is obtained.

[0067] 60 % to 90 % of the second major surface of the first luminescent element may be uncovered by the reflecting element. Alternatively, 60 % to 85 %, or 65 % to 90 %, of the second major surface of the first luminescent element may be uncovered by the reflecting element.

[0068] As an example only, 83 % of the second major surface of the first luminescent element may be uncovered by the reflecting element.

[0069] In order to maintain a high efficiency a large part of said top surface of said wavelength converter may be uncovered.

[0070] The size of the at least one first solid-state light source may be 200 pm x 300pm, the size of the reflecting element may be 300 pm x 400 pm, and the size of the first luminescent element may be 1000 pm x 1000 pm.

[0071] The reflecting element may be aligned with the at least one first solid-state light source in such a way that first solid-state light source light emitted in an angle, 0, being between 0 -10 degrees with respect to a main emission direction and not being converted by the first luminescent element is fully reflected by the reflecting element in a direction towards the first major surface of the first luminescent element.

[0072] The at least one first solid-state light source and the reflecting element may be arranged centered with respect to the first major surface and the second major surface of the first luminescent element. 2024PF80378

[0073] 8

[0074] The invention further relates to a lamp comprising a light emitting device according to the invention according to the invention.

[0075] The lamp may further comprise a light transmissive envelope at least partly enclosing the light emitting device and a base for electrically and mechanically connecting the lamp to a socket or a socket of a luminaire.

[0076] The invention still further relates to a luminaire comprising a lamp according to the invention.

[0077] The invention still further relates to a luminaire comprising a light emitting device according to the invention.

[0078] It is noted that the invention relates to all possible combinations of features recited in the claims.

[0079] BRIEF DESCRIPTION OF THE DRAWINGS

[0080] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

[0081] Fig. 1 shows a cross-sectional side view of a light emitting device according to the invention.

[0082] Fig. 2 shows atop view of the light emitting device according to Fig. 1.

[0083] Fig. 3 shows a top view of another light emitting device according to the invention.

[0084] Fig. 4 shows a cross-sectional side view of the light emitting device according to Fig. 3 seen along the line IV in Fig. 3.

[0085] Fig. 5 shows a cross-sectional side view of the light emitting device according to Fig. 3 seen along the line V in Fig. 3.

[0086] Fig. 6 shows a graph of the intensity in arbitrary units as a function of the wavelength of emission (Em; solid line) and excitation (Ex; dashed line), respectively, for a KSiF phosphor.

[0087] Fig. 7 shows a graph of the intensity in arbitrary units as a function of the wavelength of emission (Em; solid line) and excitation (Ex; dashed line), respectively, for a LuAG phosphor.

[0088] Fig. 8 shows a schematical side view of a lamp comprising a light emitting device according to the invention.

[0089] Fig. 9 shows a schematical side view of a luminaire comprising a lamp and a light emitting device according to the invention. 2024PF80378

[0090] 9

[0091] As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout.

[0092] DETAILED DESCRIPTION

[0093] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0094] Fig. 1 shows a cross-sectional side view of a light emitting device 1 according to the invention. Fig. 2 shows a top view of the light emitting device 1 according to Fig. 1. Generally, a light emitting device 1 according to the invention comprises a light exit surface 22 and is configured to, in operation, emit device light 2 from the light exit surface 22. Generally, the light emitting device 1 comprises at least one first solid-state light source 3, a first luminescent element 5, and a reflecting element 7.

[0095] The least one first solid-state light source 3 is configured to, in operation, emit first solid-state light source light 4. The first solid-state light source light 4 has a first peak emission wavelength, XI, within a wavelength range of 400 nm to 490 nm. Alternatively, the first peak emission wavelength, XI, may be within a wavelength range of 420 nm to 485 nm, or within a wavelength range of 430 nm to 480 nm, or within a wavelength range of 435 nm to 475 nm, or within a wavelength range of 440 nm to 470 nm. The first solid-state light source light 4 may have a full-width-half-maximum, FWHM, being less than or equal to 60 nm, less than or equal to 55 nm, less than or equal to 50 nm, or less than or equal to 45 nm. The at least one first solid-state light source 3 may form part of a LED package. The at least one first solid-state light source 3 further comprises a light output surface 31. The light output surface 31 of the at least one first solid-state light source 3 comprises a surface area A2 (cf. Fig. 2). The light output surface 31 comprises an edge 32, particularly a circumferential edge 32 (cf. Fig. 1). An edge axis EA extends perpendicular to the light output surface 31 and coincides with the edge 32 (cf. Fig. 1). A central axis CA extends perpendicular to the light output surface 31 (cf. Fig. 1). The least one first solid-state light source 3 comprises a length, 2024PF80378

[0096] 10

[0097] IL and a width wL. The length IL and the width wL are both in the range from 0.1 to 1 mm, preferably 0.3 to 0.8 mm.

[0098] It is noted that when referring to a solid state light source, for example the first solid-state light source 3, herein, it may be understood as referring to a light output surface of the solid state light source, for example the light output surface 31 of the first solid-state light source 3. The solid-state light source is preferably a light emitting diode (LED). Thus, the light output surface of the solid-state light source may be the light output surface of the LED.

[0099] As shown in Fig. 1, the first luminescent element 5 is arranged to cover the at least one first solid-state light source 3. It is noted that when the first luminescent element 5 is described as being arranged to cover the at least one first solid-state light source 3, this is intended to encompass both that the first luminescent element 5 is arranged in direct contact with the at least one first solid state light source, and that the first luminescent element 5 is arranged in a distance from, or in a remote configuration with, at the least one first solid-state light source 3.

[0100] The first luminescent element 5 comprises a first major surface 52 and a second major surface 53 opposite to the first major surface. The second major surface 53 forms a part of the light exit surface 22. The first luminescent element 5 further comprises a narrow-band red luminescent material 51. The first luminescent element 5 is configured to receive the solid-state light source light 4. The first luminescent element 5 is further configured to convert at least part of the solid-state light source light 4 into first converted light 6. The first converted light 6 has a second peak emission wavelength, X2, within a wavelength range of 610 nm to 650 nm. Alternatively, the second peak emission wavelength, X2, may be within a wavelength range of 615 nm to 645 nm, or within a wavelength range of 620 nm to 640 nm, or within a wavelength range of 625 nm to 635 nm, or within a wavelength range of 627 nm to 633 nm. The first converted light 6 may have multiple peak emission wavelengths. In such a case, the second peak emission wavelength, X2, may refer to a major peak emission wavelength (in the red wavelength range) for instance being from 600 nm to 690 nm. The first converted light 6 further has a full-width-half-maximum, FWHM, being smaller than or equal to 60 nm. Alternatively, the first converted light 6 may have a full-width-half-maximum, FWHM, being less than or equal to 55 nm, less than or equal to 50 nm, or less than or equal to 45 nm. The first converted light 6 may be red light. The first luminescent element 5 comprises a thickness tP, a length IP and a width wP. The thickness tP is 0.1-1 mm, preferably 0.2 to 0.7 mm. Both the length IP and the width wP are in the range from 0.5 to 5 mm, preferably 1 to 3 mm. The first part 531 of the luminescent element 5 2024PF80378

[0101] 11 covers at least 60 % and at most 90 % of the total surface area of the luminescent element 5. The second part 532 of the luminescent element 5 covers between 10 % and 40 % of the total surface area of the luminescent element 5.

[0102] Still referring to Fig. 1, the second major surface 53 comprises first part 531 and a second part 532. The first part 531 is different from the second part 532. A transition 533 is formed between the first part 531 and the second part 532. The edge 32 of the light exit surface 31 of the solid-state light source 3 is arranged with a first shortest distance, dl, to the central axis, CA. The transition 533 is arranged with a second shortest distance, d2, to the central axis, CA. By shortest distance is here meant a distance measured from the edge 32 and the transition 533, respectively, to the central axis, CA, perpendicular to the central axis, CA. The first shortest distance, dl, is smaller than or equal to the second shortest distance, d2, ie., dl < d2.

[0103] The reflecting element 7 partially covers the second major surface 53 of the first luminescent element 5. As shown in Fig. 1, the reflecting element 7 covers the second part 532 of the second major surface 53. The reflecting element 7 is aligned with the at least one first solid-state light source 3. The reflecting element 7 is more particularly aligned with the at least one first solid-state light source 3 in such a way that an angle, 0, between (i) a main emission direction of the first solid-state light source light 4 being perpendicular to the light output surface 31 and coinciding with the edge axis, EA, and (ii) a direction of emission of the first solid-state light source light 4 emerging from the edge 32 and intersecting with the transition 533 fulfills 45° > 0 > 0°, 25° > 0 > 0°, or 45° > 0 > 25°. The reflective element 7 covers between 10 % and 40 % of the total surface area of the first luminescent element 5. The reflective element 7 comprises a thickness tR, a length 1R and a width wR. Both the length 1R and the width wR are in the range from 0.02 mm to 2 mm, preferably 0.2 to 2 mm.

[0104] It is noted that the main emission direction of the first solid-state light source light 4 is parallel to the center axis CA shown in Fig. 1. The at least one first solid-state light source 3 and the reflecting element 7 are as shown in Fig. 1 and 2 arranged centered with respect to the first major surface 52 and the second major surface 53 of the first luminescent element 5.

[0105] The reflecting element 7 comprises a surface area, Al (cf. Fig. 2). The surface area, Al, of the reflecting element 7 is chosen to be larger than the surface area A2 of the light output surface 31 of the at least one first solid-state light source 3. The surface area, Al, of the reflecting element 7 may be between 5 % and 50 % larger than the surface area A2 of the light emitting surface 31 of the at least one first solid-state light source 3. In an 2024PF80378

[0106] 12 alternative, the surface area, Al, of the reflecting element 7 may be between 50 % and 100 % larger than the surface area A2 of the light emitting surface 31 of the at least one first solid- state light source 3. The surface area A2 of the light emitting surface 31 of the at least one first solid-state light source 3 may be the same as a total surface area of the at least one first solid-state light source 3. Alternatively, the surface area A2 of the light emitting surface 31 of the at least one first solid-state light source 3 may be slightly smaller than the total surface area of the at least one first solid-state light source 3.

[0107] The reflecting element 7 is diffuse reflective. The reflecting element 7 may comprise a reflectivity of at least 80 %. Between 60 % and 90 % of the second major surface 53 of the first luminescent element 5 may be uncovered by the reflecting element 7.

[0108] The at least one first solid-state light source 3 and the first luminescent element 5 are further arranged in a reflective cup 15. The reflective cup 15 is configured to direct the first converted light 6 towards the light exit surface 22. The reflective cup 15 is configured to direct the first solid state light source light 4 towards the first luminescent element 5 and / or towards the light exit surface 22.

[0109] As is shown in Fig. 2, the light emitting device 1 may further comprise a controller 23. The controller 23 is configured to control the at least one first solid-state light source 3 to vary one or more of the correlated color temperature, CCT, and the color point of the device light 2. The device light 2 is, or may be, controlled by the controller 23 to be, light having a correlated color temperature, CCT, in the range 2000 K - 6500 K and a color rendering index, CRI, of at least 80.

[0110] Fig. 3 shows a top view of another light emitting device 100 according to the invention. Fig. 4 shows a cross-sectional side view of the light emitting device 100 according to Fig. 3 seen along the line IV in Fig. 3, and Fig. 5 shows a cross-sectional side view of the light emitting device 100 according to Fig. 3 seen along the line V in Fig. 3.

[0111] The light emitting device 100 shown in Figs. 3-5 differs from the light emitting device 1 described above with reference to Figs. 1 and 2 in virtue of the following features.

[0112] The light emitting device 100 generally comprises one or more of a first further solid-state light source 8, a second further solid-state light source 9, and a third further solid-state light source 10. In the embodiment shown in Figs. 3-5, the light emitting device 100 comprises a first further solid-state light source 8, a second further solid-state light source 9, and a third further solid-state light source 10. 2024PF80378

[0113] 13

[0114] Referring to Fig. 5, the second solid-state light source 8 is configured to, in operation, emit second solid-state light source light 11. The second solid-state light source 8 is covered by a second luminescent element 12. The second luminescent element 12 comprises a narrow-band green luminescent material 121. The second luminescent element 12 is configured to receive the second solid-state light source light 11 and convert at least a part of the second solid-state light source light 11 into second converted light 13. The second converted light 13 has a third peak emission wavelength, X3, falling within the wavelength interval of 520 nm to 570 nm. The second converted light 13 may be green light. The second solid-state light source 8 is free from a reflecting element, at least on a major surface of the second luminescent element 12 forming part of the light exit surface 22 of the light emitting device 100.

[0115] Referring to Fig. 4, the third solid-state light source 9 is configured to, in operation, emit third solid-state light source light 14. The third solid-state light source light 14 has a fourth peak emission wavelength, X4, falling within the wavelength interval of 420 nm to 500 nm. The third solid-state light source light 14 may be blue light. The third solid- state light source 9 is free from a reflecting element, at least surface forming part of the light exit surface 22 of the light emitting device 100. The third solid-state light source 9 may be covered by a transparent material 24. Alternatively, the third solid-state light source 9 may be uncovered.

[0116] Referring to Fig. 5, the fourth solid-state light source 10 is configured to, in operation, emit fourth solid-state light source light 16. The at least one fourth solid-state light source 10 is covered by a third luminescent element 17. The third luminescent element 17 comprises a narrow-band yellow luminescent material 171. The third luminescent element 17 is configured to receive the fourth solid-state light source light 16 and convert at least a part of the fourth solid-state light source light 16 into third converted light 18. The third converted light 18 has a fifth peak emission wavelength, X5, falling within the wavelength interval of 575 nm to 594 nm. The third converted light 18 may be yellow light. The fourth solid-state light source 10 is free from a reflecting element, at least on a major surface of the third luminescent element 17 forming part of the light exit surface 22 of the light emitting device 100.

[0117] The first further solid-state light source 8 is arranged in a reflective cup 19 (cf. Fig 5). The reflective cup 19 is configured to direct the second converted light 13 towards the light exit surface 22. The reflective cup 19 is further configured to direct the second solid 2024PF80378

[0118] 14 state light source light 11 towards the second luminescent element 12 and / or towards the light exit surface 22.

[0119] The second further solid-state light source 9 is arranged in a reflective cup 20 (cf. Fig. 4). The reflective cup 20 is configured to direct the third solid-state light source light 14 towards the light exit surface 22.

[0120] The fourth further solid-state light source 10 is arranged in a reflective cup 21 (cf. Fig. 5). The reflective cup 21 is configured to direct the third converted light 16 towards the light exit surface 22. The reflective cup 21 is further configured to direct the fourth solid state light source light 16 towards the third luminescent element 17 and / or towards the light exit surface 22.

[0121] The reflective cups 15, 19, 20, 21 may be separate reflective cups or may be made as one element.

[0122] As is shown in Fig. 3, the light emitting device 100 may further comprise a controller 23. The controller 23 is configured to individually control the at least one first solid-state light source 3, the first further solid-state light source 8, the second further solid- state light source 9, and the third further solid-state light source 10 to vary one or more of the correlated color temperature, CCT, and the color point of the device light 2. The device light 2 is, or may be, controlled by the controller 23 to be, light having a correlated color temperature, CCT, in the range 2000 K - 6500 K and a color rendering index, CRI, of at least 80.

[0123] Referring now to Figs. 6 and 7, different suitable phosphors for a light emitting device 1 according to the invention will be described. Generally, the narrow-band red luminescent material 51 comprises a phosphor 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 tetraval ent cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. Additionally, the narrow-band red luminescent material 51 my comprise other suitable phosphors, or other suitable luminescent materials such as quantum dots.

[0124] The first luminescent element 5 may further comprises a further red luminescent material such as a broad-band red luminescent material, e.g., having a peak emission wavelength in a wavelength range from 600 nm to 670 nm and / or a full-width-half- max of at least 65 nm (or at least 75 nm) such as a (oxy)nitride phosphor. At most 30 w / w% 2024PF80378

[0125] 15 of the luminescent material in the first luminescent element may be the further red luminescent material.

[0126] KSiF class

[0127] Generally, KSiF class phosphors are suitable for use as a part of or all of the red luminescent material 51.

[0128] KSiF class phosphors are 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, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine.

[0129] Relevant alkaline cations (M) are sodium (Na), potassium (K) and rubidium (Rb). Optionally, also lithium and / or cesium may be applied. 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’xNfc- 2xAXe luminescent material has the hexagonal phase. In yet another embodiment, the M’xNfc- 2xAXe luminescent material has the cubic phase. For x=0, the composition is M2AX6. Relevant alkaline earth cations (M’) are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba.

[0130] 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. 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.

[0131] 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).

[0132] In an embodiment, M’xM2-2xAX6 comprises IGSiFe (indicated herein also as KSiF system). As indicated above, in another preferred embodiment, M’xM2-2xAX6 comprises KRbSiFe (herein also indicated as K,Rb system). As indicated above, part of 2024PF80378

[0133] 16 silicon is replaced by manganese (i.e. the formula may also be described as K2Sii-mMnmF6 or KRbSii-mMnmFe, with m as indicated above, or as KRbSiFe:Mn and K2SiFe:Mn, respectively). 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+).

[0134] In specific embodiments, the luminescent material may comprise (K,Rb)2SiF6:Mn4+. Alternatively, or additionally, in embodiments the third luminescent material may comprise K2SiFe:Mn4+. Alternatively, or additionally, in embodiments the third luminescent material may comprise K2TiFe:Mn4+. In embodiments, the third luminescent material may comprise K2(Si,Ti)Fe:Mn4+. As can be derived from the above, “Si,Ti” may indicate one or more of Si and Ti.

[0135] Fig. 6 shows a graph of the intensity in arbitrary units as a function of the wavelength of emission (Em; solid line) and excitation (Ex; dashed line), respectively, for a KSiF phosphor. KSiF phosphors can be effectively excited by a 460 nm blue LED with a strongest emission peak wavelength at near 631 nm, full width at half maxima (FWHM) smaller than 60nm with comparatively high color purity. Combined with P-SIAION green phosphor (cf. Fig. 8) for a backlight, NTSC can be improved to above 100 %. KSiF phosphors are particularly suitable for use as a part of or all of the red luminescent material 51.

[0136] Garnet class

[0137] Generally, garnet class phosphors are suitable for use as the green luminescent material 121 and as the yellow luminescent material 171. Garnet class phosphors are luminescent materials of the type AsBsOnT'e. wherein A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, especially (at least) one or more of Y, Gd, Tb and Lu, and wherein B in embodiments comprises one or more of Al, Ga, In and Sc. 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 or lutetium and wherein B comprises at least aluminum. 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); however, in addition to aluminum, B may also partly comprise gallium (Ga) 2024PF80378

[0138] 17 and / or scandium (Sc) and / or indium (In), especially up to about 20% of B, more especially up to about 10 % of B (i.e. the B ions essentially consist of 90 or more mole % of Al and 10 or less 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 (Y i-xLux)3BsOi2:Ce, wherein x is equal to or larger than 0 and equal to or smaller than 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. For instance, in the case of (Y i- xLux)3AlsOi2:Ce, part of Y and / or Lu 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). Assuming 1% Ce and 10% Y, the full correct formula could be (Yo.iLuo.89Ceo.oi)3AlsOi2. Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art.

[0139] Another suitable garnet class phosphor is a Yttrium Aluminum Garnet (YAG) phosphor. YAG phosphors are efficient and suitable for creating a high correlated color temperature (CCT). YAG phosphors exhibit absorption peaks at 450 nm, and dominant emission wavelengths range from 540 nm - 560 nm. YAG phosphors can be effectively excited by a 450 nm blue LED chip with an emission peak wavelength in the 540 nm - 560 nm range. YAG phosphors are mainly used for increasing luminous efficiency. By adding a small amount of a YAG yellow phosphor to an Ra80 LED, the luminous flux will increase dramatically. YAG phosphors are particularly suitable for use as the green luminescent material 121 and as the yellow luminescent material 171.

[0140] Fig. 7 shows a graph of the intensity in arbitrary units as a function of the wavelength of emission (Em; solid line) and excitation (Ex; dashed line), respectively, for one suitable garnet class phosphor, namely a Lutetium Aluminum Garnet (LuAG) phosphor. LuAG phosphors offer performance comparable to YAG phosphors. LuAG phosphors may have dominant emission wavelengths ranging from 520 nm to 540 nm. LuAG phosphors are generally used in conjunction with red phosphors for high CRI full spectrum coverage. LuAG phosphors can be effectively excited by a 450nm blue LED with an emission peak wavelength in the 510-540 nm range. Combined with nitride red phosphor, a high CRI spectrum with Ra above 95 can be achieved. LuAG phosphors are particularly suitable for use as the green luminescent material 121 and as the yellow luminescent material 171. 2024PF80378

[0141] 18

[0142] Fig. 8 shows an exemplary lamp 300 comprising a light emiting device 1, 100 according to any embodiment of the invention. In the embodiment shown, the light emiting device 1, 100 comprises a substantially straight light emiting device. The light emiting device of such a lamp may in other embodiments be a light emitting device with another shape, such as, but not limited to, flat.

[0143] The lamp 300 further comprises a driver or controller 305 configured for controlling the plurality of LEDs 4 of the light emiting device 1, 100. The controller 305 is configured to power the plurality of LEDs 4 via electrical circuitry (not visible on the figures) of the light emiting device 1, 100. The light emiting device 1, 100 may also comprise a controller 23, which may or may not be separate from the controller 305. In other words, the controller 305 and the controller 23 of the light emiting device 1, 100 may be integrated into one and the same driver or controller, or they may be mutually separate units.

[0144] The lamp 300 further comprises an envelope 301 at least partially enveloping the at least one light emiting device 1, 100. The lamp 300 further comprises a cap 303. As shown in Fig. 8, the controller 305 is arranged within the envelope 301. When comprising a cap 303, the controller 305 may also be arranged inside the cap 303 such that it is hidden from view. The lamp 300 further comprises threading 302 for connection to a socket, and a terminal 304 for connection to a source of electrical energy.

[0145] The envelope 301 of the lamp 300 may further and optionally be provided with a coating (not shown), such as a reflective coating, covering at least a part of the envelope 301.

[0146] Turning finally to Fig. 9, an exemplary luminaire in the form of a pendant 400 is shown. The pendant 400 comprises a light emitting device 1, 100 according to any embodiment of the invention. The light emiting device 1, 100 is as shown in Fig. 9 provided within a lamp 300 in the form of a light bulb. The light emiting device 1, 100 as shown in Fig. 9 comprises a substantially straight light emiting device.

[0147] As is also mentioned above, the light bulb further comprises a transparent envelope (cf transparent envelope 301 of lamp 300) at least partially enveloping the at least one light emiting device 1, 100. The transparent envelope may be shaped in any feasible shape, for example such as to resemble the shape of any one of a standard light bulb, a globe light bulb, a candlelight bulb, a customized light bulb and even a spiral light bulb. The transparent envelope may comprise a luminescent material. The transparent envelope may be a glass envelope. 2024PF80378

[0148] 19

[0149] The pendant 400 further comprises a socket 401 for connecting the lamp 300, and thereby the light emitting device 1, 100, to the pendant 400. The socket 401 is adapted to cooperate with the base 303 of the lamp 300. The socket 401 may comprise a threading adapted to cooperate with the threading 302 of the lamp 300. The socket 401 may comprise a terminal adapted to cooperate with the terminal 304 of the lamp 300. The pendant 400 further comprises a reflector or screen 403.

[0150] The pendant 400 may further comprise a driver 402 configured for controlling the light emitting device 1, 100. The driver 402 may or may not be the same unit as the controller 305 described above. In other words, the driver 402 and the controller 305 may be integrated into one and the same driver or controller, or they may be mutually separate units. Alternatively, or additionally, the light emitting device 1, 100 may also comprise a controller 23, which may or may not be separate from one or both of the driver 402 and the controller 305.

[0151] As shown in Fig. 9, the driver 402 is arranged on a reflector or screen 403 of the pendant 400. The driver may also be arranged within or incorporated into the reflector or screen 403. The pendant 400 further comprises an electrical wiring 404 for connection to a source of electricity, such as a mains.

[0152] It is noted that the pendant 400 shown in Fig. 9 is only one example of a luminaire according to the invention. Any suitable type of luminaire may be envisaged, such as but not limited to, a standing luminaire, a wall hung luminaire, a chandelier, a reading luminaire, an outdoor luminaire, and a table luminaire.

[0153] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims.

[0154] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0155] The term “plurality” refers to two or more.

[0156] 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%. 2024PF80378

[0157] 20

[0158] The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’.

[0159] 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".

[0160] 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.

[0161] 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.

[0162] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0163] 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”.

[0164] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Claims

2024PF8037821CLAIMS:

1. A light emitting device (1) configured to, in operation, emit device light (2) from a light exit surface (22), the light emitting device comprising: at least one first solid-state light source (3) configured to, in operation, emit first solid-state light source light (4) having a first peak emission wavelength, XI, within a wavelength range of 400 nm to 490 nm, the at least one first solid-state light source (3) comprising a light output surface (31) with an edge (32), an edge axis (EA) extending perpendicular to the light output surface (31) and a central axis (CA) extending perpendicular to the light output surface (31), a first luminescent element (5) arranged to cover the at least one first solid- state light source (3), the first luminescent element (5) comprising a first major surface (52) and a second major surface (53) opposite to the first major surface, the light exit surface (22) forming a first part (531) of the second major surface (53), the first luminescent element (5) comprising a narrow-band red luminescent material (51), the first luminescent element (5) being configured to receive the first solid-state light source light (4) and convert at least part of the first solid-state light source light into first converted light (6) having a second peak emission wavelength, X2, within a wavelength range of 610 nm to 650 nm and having a full- width-half-maximum, FWHM, being smaller than or equal to 60 nm, and a reflecting element (7), wherein the reflecting element covers a second part (532) of the second major surface (53) of the first luminescent element (5), the second part being different from the first part (531), and wherein a transition (533) is formed between the first part (531) and the second part (532), wherein the edge (32) is arranged with a first shortest distance (dl) to the central axis (CA), wherein the transition (533) is arranged with a second shortest distance (d2) to the central axis (CA), and wherein the first shortest distance (dl) is smaller than or equal to the second shortest distance (d2), wherein the reflecting element is aligned with the at least one first solid-state light source (3) such that an angle, 0, between (i) a main emission direction of the first solid- state light source light (4) being perpendicular to the light output surface (31) and coinciding with the edge axis (EA) and (ii) a direction of emission of the first solid-state light source2024PF8037822 light (4) emerging from the edge (32) and intersecting with the transition (533) fulfills 45° > 0 > 0°, and wherein the reflecting element (7) comprises a surface area, Al, facing the second major surface (53), wherein the light output surface (31) of the at least one first solid- state light source (3) comprises a surface area A2, and wherein Al > A2.

2. A light emitting device according to claim 1, wherein 25° > 0 > 0°.

3. A light emitting device according to claim 1, wherein 45° > 9 > 25°.

4. A light emitting device according to any claim 1, wherein the following applies:(i) the first part (531) is in a range of 60 % to 90 % of the second major surface (53); and(ii) the second part (532) is in a range of 10 % to 40 % of the second major surface (53).

5. A light emitting device according to any claim 1, wherein the following applies:(i) the first luminescent element (5) has a thickness in a range from 0.2 mm to 0.7 mm;(ii) the first luminescent element (5) has a width and a length in a range from1 mm to 3 mm; and(iii) the first solid-state light source (3) has a with and a length in a range from 0.1 mm to 1 mm.

6. A light emitting device according to any one of the above claims, wherein the reflecting element (7) is diffuse reflective and comprises a reflectivity of at least 80 %.

7. A light emitting device according to any one of the above claims, wherein the narrow-band red luminescent material (51) comprises a phosphor 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 tetravalent2024PF8037823 cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine.

8. A light emitting device according to claim 7, wherein at least 70 w / w% of the luminescent material in the first luminescent element (5) is the phosphor of the type M’xNfc- 2xAXe 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, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine.

9. A light emitting device according to any one of the above claims, wherein the at least one first solid-state light source (3) and the first luminescent element (5) are arranged in a reflective cup (15), the reflective cup (15) being configured to direct the first converted light (6) towards the light exit surface (22).

10. A light emitting device according to any one of the above claims, the light emitting device (1) further comprising a plurality of further solid state light sources (8, 9, 10), wherein the plurality of further solid state light sources comprises: at least one second solid-state light source (8) configured to, in operation, emit second solid-state light source light (11), the at least one second solid-state light source (8) being covered by a second luminescent element (12), the second luminescent element (12) comprising a green luminescent material (121), the second luminescent element (12) being configured to receive the second solid-state light source light (11) and convert the second solid-state light source light (11) into second converted light (13) having a third peak emission wavelength, X3, within a wavelength range of 500 nm to 570 nm, the second solid- state light source light (11) being green light; at least one third solid-state light source (9) configured to, in operation, emit third solid-state light source light (14) having a fourth peak emission wavelength, X4, within a wavelength interval of 420 nm to 490 nm, the third solid-state light source light (14) being blue light; and at least one fourth solid-state light source (10) configured to, in operation, emit fourth solid-state light source light (16), the at least one fourth solid-state light source (10) being covered by a third luminescent element (17), the third luminescent element (17) comprising a green-yellow luminescent material (171) and a red luminescent material (172),2024PF8037824 the third luminescent element (17) being configured to receive the fourth solid-state light source light (16) and convert the fourth solid-state light source light (16) into third converted light (18) having a fifth peak emission wavelength, X5, falling within the wavelength interval of 500 nm to 660 nm, the fourth solid-state light source light being white light having a correlated color temperature in a range from 2000K to 6500K and a color rendering index of at least 70.

11. A light emitting device according to claim 10, wherein one or more of the following applies: the third solid-state light source (9) is free from a reflecting element arranged on a part of a major surface of the second luminescent element (12) forming a part of the light exit surface (22), and the fourth solid-state light source (10) is free from a reflecting element arranged on a part of a major surface of the third luminescent element (17) forming a part of the light exit surface (22).

12. A light emitting device according to claim 10 or 11, wherein one or more of the following applies: the one or more of the further solid state light sources (8, 9, 10) is / are arranged in a respective reflective cup (19, 20, 21) configured to direct the second converted light (11), the third solid-state light source light (14) and the third converted light (18), respectively, towards the light exit surface (22), and the at least one third solid-state light source (9) is covered by a transparent material (24), or wherein the at least one third solid-state light source (9) is uncovered.

13. A light emitting device according to any one of the above claims, wherein the at least one first solid-state light source (3) and, where provided, the one or more further solid state light sources (8, 9, 10) form part of a LED package.

14. A light emitting device according to any one of claims 10 to 13, and further comprising a controller (23) configured to individually control the at least one first solid-state light source (3) and, where provided, the one or more further solid state light sources (8, 9, 10) to vary one or more of the correlated color temperature, CCT, and the color point of the device light (2), and wherein the device light (2) is light having a correlated color2024PF8037825 temperature, CCT, in the range 2000 K - 6500 K and a color rendering index, CRI, of at least 80.

15. A lamp (300) or a luminaire (400) comprising a light emitting device (1) according to any one of the above claims.

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