High color gamut photoluminescence wavelength converted white light emitting device

Abstract

To provide photoluminescence wavelength converted light emitting devices including multiple quantum well (MQW) dual-wavelength light emitting diodes (LEDs) that generate both narrowband blue and narrowband green light emissions to improve the color gamut of backlights.SOLUTION: A white light emitting device (backlight) includes a multiple quantum well (MQW) dual-wavelength LED, and a narrowband photoluminescence material that generates red light with a peak emission wavelength from about 620 nm to about 660 nm. The MQW dual-wavelength LED includes at least one first quantum well (QW) that generates blue light with a dominant wavelength of 440-470 nm, and at least one second quantum well (QW) that generates green light with a dominant wavelength of 520-540 nm.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. Provisional Patent Application No. 62 / 924,744, filed October 23, 2019. No. 7, filed on May 23, 2007, which claims the benefit of priority to US Pat. No. 6,313,363, the entire contents of which are incorporated herein by reference.

[0002] Embodiments of the present invention relate to photoluminescent wavelength-converted white light-emitting devices. Specifically, but not exclusively, embodiments are directed to color liquid crystal displays (LCDs). It targets high color gamut devices. [Background technology]

[0003] Photoluminescent wavelength-converted white light-emitting devices, often referred to as "white LEDs" Typically, the LED contains a blue LED and absorbs a portion of the blue light emitted by the LED. , one or more photoluminescent materials (typically Such white LEDs use blue pumped These are called photoluminescent wavelength-converted white LEDs. A portion of the blue light generated by the LED is emitted by the phosphor. When combined with light, it provides a light that appears white to the eye. General Lighting and Color For backlighting for LCDs, white LEDs typically use yellow to green and red LEDs. It contains a combination of photoluminescent materials that emit light. Its long operating life (>50 ,000 hours) and high luminous efficacy (over 100 lumens per watt) make it a Color LEDs are replacing traditional fluorescent, compact fluorescent, and incandescent lamps in general lighting applications. is rapidly replacing.

[0004] Color LCDs are used in televisions, computer monitors, laptops, tablet computers, The present invention finds application in a variety of electronic devices, including computers, smartphones, and the like. In addition, most color LCDs use a liquid crystal (LC) display panel and and a white-emitting backlight for driving the LEDs. ional Television System Committee NTSC c The CIE 1931 (CIE 1953) RGB color space standard is a standard for LCD displays. These are two of the most important parameters for the color quality of a display, and they depend on the backlight. The white LEDs used in the display and the RGB (red, green, blue) color filters Determined by the spectrum of light produced. Currently used in LCD backlights. The majority of white LEDs in use today are blue-pumped wavelength-converted white LEDs. The ideal white light spectrum for a display corresponds to the RGB color filters of the display. The narrowband red, narrowband blue, and narrowband green emission peaks have peak emission wavelengths corresponding to the Over the past 15 years, the number of white LEDs used for LCD backlighting has increased. a) The narrowband blue emission peak produced by the LED, as well as the green silicate and red broadband green and broadband red emission peaks produced by phosphors such as color nitrides, b) A narrowband blue emission peak produced by an LED and a yellow phosphor such as YAG Its spectrum consists of a single broadband yellow emission peak produced by For white LEDs in backlights, it has a narrowband red emission peak at about 631 nm. Manganese-activated fluoride phosphors are used. However, they have a narrowband green emission and Suitable phosphors with full width at half maximum (FWHM) less than 40 nm enable high color gamut displays is not available to

[0005] The present invention overcomes, at least in part, the limitations and shortcomings of existing backlights and provides an LC It arose from an attempt to improve the color gamut of backlights for D displays. Summary of the Invention

[0006] An embodiment of the present invention provides a multiple quantum dot laser that produces both narrowband blue and narrowband green emissions. Photoluminescence wavelength conversion, including multi-quadrature well (MQW) dual-wavelength light-emitting diodes (LEDs) In this patent specification, the MQW dual wavelength LED is a blue and A single LED die (or An LED die is defined as a single LED chip. An LED die can be a monolithic structure. The quantum wells that generate the blue and green light are integrated on a single chip. or blue / green light generating quantum dots that combine to generate both blue and green light. The LED structure may include a single quantum well that produces either blue or green light. or both, by themselves, contain multiple blue or green quantum wells. That is, either or both of the blue or green quantum wells may comprise an MQW structure.

[0007] According to an embodiment, a MQW dual wavelength LED and a peak emission wavelength of about 620 nm to about 660 nm are provided. radiation wavelength (λ pe and a narrow band photoluminescent material that produces red light having a The light emitting device (backlight) is provided, and the MQW dual wavelength LED is 440nm~4 Dominant wavelength (λ d1 At least one blue light generating device having First quantum well (QW), and dominant wavelength (λ ) of 520 nm to 540 nm d2 )of and at least one second QW for generating green light having a MQW dual wavelength LE. D produces narrowband blue and narrowband green emission, and the narrowband photoluminescent material is To produce narrowband red emission, the devices of the present invention are comparable to known devices and structures. The luminous flux is operable to produce light having a superior color gamut compared to conventional luminous flux.

[0008] In an embodiment, the multiple quantum well dual wavelength LED comprises a plurality of first quantum wells and a plurality of second quantum wells. 2 quantum wells, i.e., producing blue or green light. One or both of the quantum wells constitute an MQW structure. The blue and green MQW structures are in separate areas of a single chip (monolithic device), or blue and green A single blue / green MQW structure where the two quantum well structures are assembled in the same area of ​​the chip. For example, a M 2000 MHz MOS 8 ... , which includes stacks of interleaved (e.g., alternating) blue and green QWs, It can be assembled as a QW structure layer.

[0009] In an embodiment, the blue light and / or the green light may be, for example, from about 15 nm to about 45 nm, about The FWHM radiation intensity may be between 25 nm and 45 nm, or between about 15 nm and about 25 nm. The FWHM radiant intensity of the blue light generated by the dual-wavelength LED is Select by configuring the indium doping concentration, width, number and dominant wavelength interval. Similarly, the FWHM radiant intensity of the green light generated by the dual-wavelength LED is , configuring the indium doping concentration, width, number and dominant wavelength spacing of the second QW; can be selected by

[0010] In embodiments, the narrowband red photoluminescent material may be, for example, from about 5 nm to about 30 nm. m, or FWHM radiance of about 10 nm to about 25 nm. The luminescent material has a peak emission wavelength (λ) of about 620 nm to about 640 nm. pe ) red Narrow band photoluminescent materials can be inorganic and / or organic. may include organic phosphor materials, quantum dot (QD) materials, dyes, as well as combinations thereof. .

[0011] In an embodiment, the blue and green light include respective peaks, and the peak of the blue light peak The ratio of the peak radiant intensity of the green light peak to the radiant intensity is at least 30%, at least 40%, at least 50%, at least 60%, 30%-60%, 30%-50%, 30 %~40%, 40%~50%, 40%~60%, or 50%~60%.

[0012] In some embodiments, the photoluminescent material is a manganese activated fluoride phosphor. The light-emitting device contains manganese-activated fluoride phosphors in combination with MQW dual-wavelength LEDs. Narrow-band photoluminescent devices have been found to produce light with a particularly good color gamut. The sensing material is a manganese-activated fluoride phosphor, specifically K2SiF6:Mn 4+ Implementation form including In this state, the device uses NTSC (National Television System) m Committee NTSC colorimetry 1953(CIE 19 31))RGB color space standard and / or DCI-P3 (Digital Cinema It has a color gamut that is at least 90% of the area of ​​the RGB color space standard (Initiative) In an embodiment, the photon beam of manganese activated fluoride can generate light having a spectrum. The luminescent material has a dominant peak emission wavelength of about 630 nm to about 632 nm. Red light producing K2SiF6:Mn 4+ In an embodiment, manganese activated fluoride may be used. The photoluminescent material of the compound is K2TiF6:Mn 4+ In an embodiment, The manganese-activated fluoride photoluminescent material is K2GeF6:Mn 4+ Includes The manganese activated fluoride photoluminescent material is also K2SnF6:Mn 4 + , Na2TiF6:Mn 4+ , Na2ZrF6:Mn 4+ , Cs2SiF6:Mn 4+ , Cs2TiF6:Mn 4+ , Rb2SiF6:Mn 4+ , Rb2TiF6:Mn 4+ , K3ZrF7:Mn 4+ , K3NbF7:Mn 4+ , K3TaF7:Mn 4+ , K3Gd F6:Mn 4+ , K3LaF6:Mn 4+ , and K3YF6:Mn 4+ From the group consisting of It may include a selected general composition.

[0013] In an embodiment, the narrow band photoluminescent material is MSe 1-x S x Based on :Eu Europium-activated sulfide phosphors such as sulfide selenide phosphors of the IIA / IIB group of general compositions The phosphor may include a monophosphor, wherein M is at least one of Mg, Ca, Sr, and Ba. One example of such a phosphor material is calcium selenium sulfide "CSS" phosphor (CaS e 1-x S x To improve reliability, europium activated selenium sulfide is used. The particles of phosphor material may be made of one or more oxides, such as aluminum oxide (Al2O3), oxide Silicon oxide (SiO2), titanium oxide (TiO2), zinc oxide (ZnO), magnesium oxide Magnesium oxide (MgO), zirconium oxide (ZrO2), boron oxide (B2O3), or quartz oxide It can be coated with CrO.

[0014] In embodiments, the narrow band photoluminescent material may include a quantum dot (QD) material. In a preferred embodiment, the quantum dot material is cadmium selenide (CdSe-FWHM). M

number

number

number

number

[0015] In some embodiments, the light emitting device is configured such that the photoluminescent material is a MQW dual-wave The packaging arrangement may include a package that is disposed over a long LED, e.g., a photoluminescent material. Materials include, but are not limited to, surface mounted device (SMD) package configurations, including LEDs. Alternatively, the photoluminescent material may be disposed in a package having a chip scale. The GaN LEDs can be deposited directly onto individual LED dies in a chip-package (CSP) arrangement.

[0016] In other embodiments, the light emitting device may be a remote photoluminescent (e.g., a remote phosphor ) arrangement, where the photoluminescent material is located remotely relative to the LED. For example, the photoluminescent layer may include a photoluminescent sheet. In the Subsection, "remotely" means in a distant or separate relationship. The separation can be an air gap or between the LED and the photoluminescent layer / sheet. Such a remote phosphor arrangement may be used in display backlighting. The photoluminescent layer may find particular application in display devices, It may include.

[0017] In various embodiments, the photoluminescent material may be dispersed in an optically transmissive medium. The optically transparent medium may include dimethyl silicone or phenyl silicone. For a better match with the refractive index of the photoluminescent material, the photoluminescent Based on the composition of the sensing material, phenyl silicone (refractive index about 1.54) or diphenyl silicone are used. For example, K2SiF6:M n 4+ (refractive index 1.4) may be dispersed in dimethyl silicone, while K2TiF 6:Mn 4+ (Refractive index > 1.5) may be dispersed in phenyl silicone.

[0018] The light emitting device of the present invention arises in relation to backlighting for color LCDs. A light-emitting device including a MQW dual-wavelength LED and a red photoluminescent material is They can also find utility in general lighting applications, such as MQ W dual wavelength LEDs have a dominant wavelength of 500nm~560nm and a wider full width at half maximum. Width (FWHM) of radiation intensity, e.g., about 15 nm to about 60 nm, about 25 nm to about 60 nm or to generate blue light and / or green light having a wavelength of about 45 nm to about 60 nm. In general lighting applications, for example, red photoluminescent materials can be configured to emit light at 60 The wavelength of peak radiant intensity may be between 0 nm and 660 nm, which is the orange portion of the visible spectrum. The red photoluminescent material has the general composition CaAlSi N3:Eu(CASN) or (Sr,Ca)AlSiN3:Eu(SCASN) Europium-activated nitride photoluminescent materials such as europium aluminum silicon nitride phosphors In addition, the photoluminescent material may include a broadband red photoluminescent material. The luminescent material may include a narrow band red photoluminescent material. Packaging arrangement, e.g. SMD packaging arrangement, Chip on Board (COB), LE D filament - Chip on Glass (COG) and Chip Scale Package (CS P) arrangement, or a remote phosphor arrangement. [Brief description of the drawings]

[0019] These and other aspects and features of the present invention are best understood by reference to certain specific embodiments of the invention when taken in conjunction with the accompanying drawings. This will become apparent to those skilled in the art upon review of the following description of the embodiments.

[0020] [Figure 1] FIG. 2 is a cross-sectional side view of a packaged photoluminescent wavelength-converted white light-emitting device according to an embodiment of the present invention. [Diagram 2] 2A, 2B, and 2C are schematic diagrams of an exemplary multiple quantum well (MQW) dual wavelength LED chip structure. [Diagram 3] 3A and 3B are (a) a top view and (b) a cross-sectional side view through AA, respectively, of a chip-on-board (COB) packaged white light-emitting device according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a chip-scale package (CSP) white light-emitting device utilizing a flip-chip dual-wavelength LED die according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of a chip-scale packaged (CSP) white light-emitting device utilizing a lateral-chip dual-wavelength LED die according to an embodiment of the present invention. [Figure 6] FIG. 1 is a schematic diagram of a chip-scale packaged (CSP) white light-emitting device utilizing a vertical-chip dual-wavelength LED die according to an embodiment of the present invention. [Figure 7] 7A and 7B are (a) a plan view and (b) a cross-sectional side view through BB, respectively, of a remote photoluminescent white light-emitting device according to an embodiment of the present invention. [Figure 8] 8A and 8B are cross-sectional side views, respectively, of (a) an edge-lit liquid crystal display according to an embodiment of the invention, and (b) a display backlight according to an embodiment of the invention. [Figure 9] 1 is a schematic cross-sectional view of a direct-lit backlight according to an embodiment of the present invention. [Figure 10] 1 is a schematic cross-sectional view of a direct-lit backlight according to an embodiment of the present invention. [Figure 11] 1 is a schematic cross-sectional view of a direct-lit backlight utilizing a remote phosphor film according to an embodiment of the present invention. [Figure 12] 1 shows the emission spectrum of manganese-activated potassium hexafluorosilicate phosphor (KSF) of general composition K2SiF6:Mn4+. [Figure 13] 1 shows normalized emission spectra of CSS phosphors (designated CSS604, CSS615, CSS624, CSS632, and CSS641) for different ratios of S / Se (sulfur / selenium). [Figure 14] Measured emission spectrum of intensity versus wavelength for a multiple quantum well (MQW) dual wavelength LED. [Figure 15] Measured emission spectra of intensity versus wavelength for a packaged light emitting device (backlight) according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Now, the embodiments of the present invention will be described in detail with reference to the drawings, which are easily understood by those skilled in the art. It is provided as an illustrative embodiment of the invention in order to enable the practice of the invention. In addition, the following figures and examples are not intended to limit the scope of the invention to a single embodiment. by replacing some or all of the elements described or illustrated. Other embodiments are possible. Additionally, certain elements of the invention may be implemented using known components. If the invention can be implemented in part or in full, such Only those portions of such known components are described, so as not to obscure the present invention. Detailed description of other parts of such known components will be omitted. The illustrated embodiments of the elements should not be considered limiting, but rather the present invention is Other embodiments including multiple identical components, unless expressly stated otherwise in the specification, and The converse is intended to be encompassed. Further, applicants expressly disclaim all such disclosure. Unless otherwise specified, any term in the specification or claims is intended to be used without reference to a general or specific Moreover, the present invention is not intended to be construed as being limited to the specific embodiments described herein, but rather to be limited to the embodiments described herein by way of example only. This specification includes all currently and future known equivalents to the known components referenced herein. Throughout the figures, like reference numbers precede like reference numbers to indicate like (equivalent) parts. It is used for this purpose.

[0022] An embodiment of the present invention is a dual-wavelength LED that produces blue and green light emissions. As described above, the MQW dual-wavelength LE D is a single LED die that produces two (dual) different colors (wavelengths) of blue and green light. (or tip).

[0023] Packaged White Light Emitting Device / Backlight Here, a packaged photoluminescent wavelength-converted white light emitter according to an embodiment of the present invention is shown. The light device 110 is described with reference to FIG. 1, which shows a cross-sectional side view of the light emitting device 110. The light emitting device 110 may be, for example, a surface mount device (SMD) 2835 LED package. A package type device that includes a lead frame 112. SMD package 112 has a generally rectangular base 114 and upwardly extending ends 116 extending from opposing edges of the base 114. The inner surfaces of the side walls 116a, 116b are shown. 114, the inverted pyramid 114 is inclined vertically outward from the base 114. A cavity 118 in the shape of a frustum is defined.

[0024] In this embodiment, the cavity 118 contains one or more dual wavelength LED dies 120 (FIG. 1 shows one 102 includes a red emitting photoluminescent material filling cavity 118. The photoluminescent layer 122 contains a red photoluminescent material of 620 Peak emission wavelength (λ pe ) to generate red light having It is possible to move.

[0025] The LED dies 120 are mounted on respective bonding pads 124 on the floor of the cavity 118. The or each LED die 120 has n-electrodes 12 on opposing ends of its top surface. 6a and p-electrode 126b. Bond wires 128a, 128b are connected to n-electrode 126a. and p-electrode 126b is connected to a corresponding contact pad 130 mounted on the floor of cavity 118. The contact pads 130a and 130b are connected to the exterior of the lower surface of the base 114. Electrically connected to contact pads 132a and 132b.

[0026] The photoluminescent layer 122 is typically made of a light-transmitting material such as, for example, a silicone material. The phosphor material may be in the form of particles dispersed in a transparent optical enclosure (medium). The photoluminescent layer 122 is in contact with the LED die 120 as shown. Depending on the device application, the cavity 118 may be filled with photoluminescence. The sense material can be broadband (FWHM radiation intensity of about 25 nm to about 60 nm) or narrowband (about It can be a material suitable for device applications with a FWHM radiation intensity of 5 nm to about 25 nm. Examples of broadband and narrowband red photoluminescent materials are described below.

[0027] MQW dual wavelength LED In accordance with the present invention, the MQW dual wavelength LED die 120 has: a) a wavelength of 440 nm to 470 nm; Dominant wavelength (λ d1 One or more first quantum wells that generate blue light during operation, (QW), and b) dominant wavelengths (λ d2 ) green InGaN / GaN (Indium Nitride) containing one or more second QWs that generate light during operation. The LED die may include a MQW (Mg / GaN) dual wavelength LED die. The dual-wavelength LED includes a plurality of first and second quantum wells, i.e., first and second quantum wells. Each of the QWs itself comprises a respective MQW structure.

[0028] 2A, 2B and 2C are diagrams illustrating an exemplary MQW dual wavelength LED that can be used in the present invention. 1 is a schematic diagram of the structure. There are other suitable MQW LED structures that are suitable for use in the present invention. It will be understood that Figures 2A and 2B show the same components assembled as a single chip. The present invention is monolithic in that it essentially comprises respective blue and green MQW LED structures. 2C is sometimes referred to as a thick device, while FIG. 2C is a device that produces blue and green light. The LED structure may include a single MQW.

[0029] Referring to FIG. 2A, the LED chip 220 includes, in order, a sapphire substrate 220a, a first n-doped GaN (n-GaN) layer 220b, dominant wavelength λ d2 To generate green light The second InGaN MQW structure layer 220c for the first p-doped GaN (p-GaN) layer 220d, a barrier layer 220e, a second n-doped GaN (n-GaN) layer 220f, and a domina Wavelength λ d1 a first InGaN MQW structure layer 220g for generating blue light; and a second p-doped GaN (p-GaN) layer 220h. 26a and p-electrode 226b are the first n-GaN layer 220b and the second p-GaN layer 226c, respectively. The MQW structures 220c and 220g are electrically connected to the GaN layer 220h. The dominant wavelength λ of the light generated d is the indium (In) doping of the QW, and the width of the QW layer , and the number of QWs and the dominant wavelength λ d The spacing may depend on the layers 220b to 220d. The structure includes a respective green MQW LED structure (p-n junction die) that produces green light. The structure including layers 220f to 220h constitutes a blue light generating layer, while the structure including layers 220f to 220h constitutes a blue light generating layer, It will be understood that the green and blue MQW LED structures are constructed in the same manner. The LED structures are electrically connected in series. Depending on the application, blue (first) and Number of green (second) QWs and dominant wavelength λ d The spacing is about 15 nm to about 45 nm. The blue and / or green light may be configured to generate a radiant intensity of For example, in general lighting applications, blue and / or green light is typically In addition, it has a wider FWHM radiation intensity, for example, from about 25 nm to about 645 nm. In backlight applications, blue and / or green light generally has a narrower FWHM It has a radiation intensity, for example, from about 15 nm to about 25 nm.

[0030] In the arrangement of FIG. 2A, blue (first) and green (second) MQW layers 220g and 22 0c are stacked on top of each other in a vertical arrangement. In another embodiment, blue and green Q W can be located laterally in a single layer. Referring to FIG. 2B, the LED chip 220 includes, in order, a sapphire substrate 220a, an n-doped GaN (n-GaN) layer 220b, Dominant wavelength λ d1 of blue light and dominant wavelength λ d2 green light and The first and second InGaN MQW structures 220g, 220c for As shown in FIG. 2B, the first and the second MQW structure 220g, 220c is laterally located within a single layer and has a barrier The n-electrode 126a and the p-electrode 126b may be separated by a layer 220e. The n-GaN layer 220b and the p-GaN layer 220h are electrically connected to the layer 220b. The structure including 220g and 220h has blue MQW LEs that generate blue light. D structure (pn junction diode), while layers 220b, 220c and 220h Each of the structures may comprise a green MQW LED structure that produces green light. As will be appreciated, the blue and green MQW LED structures are electrically connected in parallel. The dominant wavelength λ of the light generated by the blue and green MQW structures is d Is Injiu The In doping, width of the QW layers, and the number of QWs and dominant wavelength λ d Depends on interval Depending on the application, the number and dominance of the blue (first) and green (second) QWs can be adjusted. wavelength λ d The interval is blue with a radiation intensity of about 15 nm to about 45 nm full width at half maximum (FWHM). It may be configured to generate colored and / or green light, e.g., for general lighting applications. In the 3D laser, blue and / or green light generally has a broader FWHM radiant intensity, e.g. About 25 nm to about 45 nm. For display backlight applications, blue light and / or Alternatively, green light generally has a narrower FWHM radiant intensity, for example, from about 15 nm to about 25 nm. has.

[0031] Figure 2C shows a single MQW LED structure capable of generating both blue and green light. 2C, the LED chip 220 is, in turn, mounted on a sapphire substrate 22 0a, n-doped GaN (n-GaN) layer 220b, dominant wavelength λ d2 Produces green light A second InGaN MQW structure layer 220c for achieving a dominant wavelength λ d1 of blue light The first InGaN MQW structure layer 220g and the a-doped GaN (p- The layered structure includes a GaN layer 220h. The n-electrode 226a and the p-electrode 226b are They are electrically connected to the n-GaN layer 220b and the p-GaN layer 220h, respectively. Dominant wavelength .LAMBDA. of light generated by color and green MQW structures d is the indicator of QW The In doping, width of the QW layers, and the number of QWs and dominant wavelength λ d Depends on the interval The structure including layers 220b, 220c, 220g, and 220h may be used to produce blue and green By constructing a single MQW LED structure (pn junction diode) that produces both colors of light, It will be appreciated that depending on the application, the number and Dominant wavelength λ d The interval is the full width at half maximum (FWHM) radiation intensity of about 15 nm to about 60 nm. For example, the common In lighting applications, blue and / or green light generally has a wider FWHM radiant intensity. For example, about 25 nm to about 60 nm. For display backlight applications, blue The green and / or red light generally have a narrower FWHM radiant intensity, e.g., about 15 nm to As shown, the green (second) MQW structure 220c has a a GaN layer 220b, and a blue (first) InGaN MQW structure layer 220c. g is disposed on top of the blue InGaN structural layer 220g and adjacent to the p-GaN layer 220h. In other configurations, the positions of the blue and green MQW structure layers are arranged on the n-GaN layer. A blue (first) MQW structure 220g located adjacent to 220b, and a p-GaN layer 2 20h, and can be transposed with the green (second) MQW structure layer 220c located adjacent to Furthermore, the MQW structure layers 220c and 220g are each a stack of MQW layers. Although illustrated as including a QW structure, the first and second MQWs may be a single structure, e.g. For example, a single MQW containing a stack of interleaved (e.g., alternating) blue and green QWs. It may be integrated as a structural layer.

[0032] Referring to FIG. 1, during operation, a portion of the blue light from the dual wavelength LED die 120 is directed toward the photodiode. The red light is converted to red light by the photoluminescent material in the luminescent layer 122 . Green light generated by dual wavelength LED die 120, photoluminescent material The combination of red light generated by the dual-wavelength LED die and unconverted blue light generated by the dual-wavelength LED die. The combination produces a white luminescent product. Depending on the characteristics of the dual-wavelength LED die, some of the green light generated by the dual-wavelength LED die may also be photoinduced. It is possible that this can be converted to red light by a luminescent material.

[0033] Here, according to an embodiment of the present invention, chip-on-board (COB) packaging A white light emitting device 310 is described with reference to Figures 3A and 3B. Multiple (12) MQW dual-wavelength LED dies 320 disposed on a substrate 314, and a LE The D die 320 includes a photoluminescent material 322 disposed on the D die 320. More specifically, FIG. 3A shows a plan view of a COB white light emitting device 310, and FIG. 3B shows an A- The cross-sectional side view through A is shown. The substrate 314 is planar and square in shape, and has a metal core. The twelve dual-wavelength LED dies 320 are circular. The devices 310 are distributed evenly on the substrate 314 in the form of an array. The LED die 320 includes an array of LED dies 320, and is circular in shape with the surface of the substrate 314. The LED die 320 includes an annular wall 316 that defines a cavity 318. Dominant wavelength λ of m d1 Blue light with dominant wavelengths of 520nm to 540nm wavelength λ d2 The optical fiber is operable to generate green light having a

[0034] Red photoluminescent material 322 is deposited on the substrate 314 within the walls 316. It completely covers the ED die 320 and fills the cavity 318. 2, the peak emission wavelength λ of 620nm~660nm pe To generate red light having It is operational.

[0035] During operation, a portion of the blue light generated by the LED die 320 is photoluminescent. The green light produced by the LED die 320 is converted to red light by the photo The red light produced by the luminescent material and the unproduced light produced by the LED die The combination of the blue light in the conversion produces a white luminescent product.

[0036] Optionally, the white light emitting device 310 includes a diffusing layer 334 (indicated by the dashed line in FIG. 3B ). The diffusing layer may improve the color uniformity of the light emitted by the white light emitting device 310. The diffusing layer may be in direct contact with the photoluminescent material 322. The enhanced color uniformity is achieved when the device is This can be particularly advantageous when used in large beam optical systems. By directing the blue excitation light back into the photoluminescent material 322, the photons are converted into photons. This increases the probability of generating more blue excitation light. is converted to photoluminescent light by the diffusing layer, producing light of a given color temperature. This reduces the amount of photoluminescent material required for photoluminescence. Reducing the amount of luminescent material is particularly important in the case of expensive manganese activated fluorine such as KSF. It is more cost-effective to manufacture the white light emitting device 310 when using fluoride phosphors. Provide a format that is easy to understand.

[0037] Referring now to FIG. 4, a flip chip LED die 42 according to an embodiment of the present invention. A schematic diagram of a chip-scale package (CSP) white light-emitting device using 0 is shown. is.

[0038] CSP White Light Emitting Device 410 MQW Dual Wavelength LED Flip Chip LED Die 4 20, each of whose light-emitting surfaces (typically the top and four sides) is provided with a red photoluminescence The LED die 422 has a coating layer 422 of emissive material. Dominant wavelength λ of 70 nm d1 Blue light with 520nm to 540nm Nantes wavelength λ d2 The red photoluminescent device is operable to generate green light having a red photoluminescent The sense material 422 has a peak emission wavelength λ of 620 nm to 640 nm. pe A red light having The LED die 420 has an n-electrode 426a and a p-electrode 426b at its base 436. The n-electrode 426a and the p-electrode 426b are connected to two corresponding bonding pads. 430a, 430b are electrically connected by flip chip bonding 434a and 434b. The contact pads 430a, 430b are mounted on a planar substrate 414. .

[0039] Referring to FIG. 5, a lateral chip dual wavelength LED die 520 according to an embodiment of the present invention. A schematic diagram of a CSP white light emitting device utilizing is shown.

[0040] The light emitting device 510 includes a MQW dual wavelength LED die 520 having a top portion 538b and a bottom portion 538c. and coated on all sides 538a, 538c with red photoluminescent material 522. The LED die 520 has a bond pad 524 attached to its base 536. The LED die 520 includes an MQW structure and has a dominant wavelength of 440 nm to 470 nm. Wavelength λ d1 Blue light having a dominant wavelength λ of 520 nm to 540 nm d2 of The red photoluminescent material 522 is operable to produce green light having a , Peak emission wavelength λ of 620nm~640nm pe It produces red light with LEDs. The semiconductor device 520 has an n-electrode 526a and a p-electrode 526b at opposite ends of its upper surface 538b. The bond wires 528a, 528b connect the n-electrode 524a and the p-electrode 524b in a planar manner. It connects to corresponding contact pads 530 a , 530 b mounted on the face substrate 514 .

[0041] Referring to FIG. 6, a vertical chip dual wavelength LED die 62 according to an embodiment of the present invention. A schematic diagram of a CSP white light emitting device utilizing ZnO-based ZnSe is shown.

[0042] The light emitting device 610 includes a MQW dual wavelength LED vertical chip LED die 620. Only the top surface 638b is coated with red photoluminescent material 622. More specifically, a vertical chip emits light only from its top surface, so the side 638 a, 638c are not coated with photoluminescent material. LED die 6 20 includes an MQW structure and has a dominant wavelength λ of 440 nm to 470 nm d1 Blue with Color light, and dominant wavelength λ of 520nm~540nm d2 to produce green light having The die 620 includes an n-electrode 626a at its base 626, Pole 626a sits on bonding pad 632. In turn, bonding pad 63 2 sits on contact pads 630a, which are mounted on a planar substrate 614. The LED die 620 includes a p-electrode 624b on one end of its top surface 638b. Wire 624 connects p-electrode 624b to a corresponding contact pad mounted on planar substrate 614. The red photoluminescent material 622 is connected to a lead 630b. m peak emission wavelength λ pe The light source is operable to generate red light having a

[0043] Remote photoluminescent white light-emitting device The present invention relates to a packaged white light emitting device in which the photoluminescent material is LE A remote photoluminescence device including a photoluminescent layer located remotely relative to the die. The present invention also finds utility in remote phosphor (e.g., remote phosphor) configurations. "Separate" means in a spaced or separated relationship. Separation includes air gaps. or a light-transmitting medium between the LED die and the photoluminescent layer. may include.

[0044] Here, a remote photoluminescent wavelength-converted white light-emitting device according to an embodiment of the present invention is The arrangement 710 of the sensors is described with reference to Figures 7A and 7B. More specifically, Figure 7A shows: FIG. 7B shows a partial cross-sectional plan view of a remote photoluminescent white light-emitting device 710. A cross-sectional side view through BB (of FIG. 7A) is shown.

[0045] The device 710 may be used alone or in conjunction with a downlight or other lighting arrangement. The device 710 may include a circular, disk-shaped base 742, a hollow cylinder, A hollow cylindrical book having a wall portion 744 and a removable annular top portion 746. To aid in heat dissipation, the base 742 may be made of aluminum, The heat sink may be made of aluminium alloys or any material with high thermal conductivity.

[0046] The device 710 is thermally coupled to a circular shaped MCPCB (metal core printed circuit board) 748. Multiple (five in the example of Figures 1A and 1B) packages mounted in communication The device 71 further includes an MQW dual wavelength LED 720. 0 are light-reflecting surfaces covering the surface of the MCPCB 748 and the inner curved surface of the cylindrical wall 744, respectively. Each of the LEDs 720 may further include a MQW structure. Dominant wavelengths (λ d1 ) blue light, and 52 The LED is operable to generate green light having a dominant wavelength between 0 nm and 540 nm.

[0047] The device 710 is located remotely with respect to the LED 720 and emits a They absorb a portion of the blue / green excitation light and convert it into light through the process of photoluminescence. Contains a red photoluminescent material that is operable to convert light of a different wavelength The red photoluminescence wavelength conversion element 722 is further included. The lasing material 722 has a peak emission wavelength (λ pe ) red light The radiation product of the device 710 is illuminated by the LED 720. The blue and green light generated by the photoluminescent wavelength conversion component 722 is Photoluminescence wavelengths The conversion component is a light-transmitting material (e.g., For example, the material may be polycarbonate, an acrylic material, a silicone material, etc. In an embodiment, the photoluminescent wavelength converting component is a red photoluminescent The wavelength converting component may be formed from a light-transmitting substrate that is coated with a material. 722 is positioned remotely relative to the LED 720 and spatially separated from the excitation source. In patent specifications, "remotely" and "remote" mean in a distant or separated relationship. Typically, the wavelength conversion component and the excitation source are separated by air. However, in other embodiments, they may be made of, for example, light-transmitting silicone or epoxy materials. The wavelength conversion component 722 may be separated by a suitable optically transparent medium such as a The housing is opened so that all light emitted by the wavelength component 722 passes through the As shown, the wavelength converting component 722 is configured to completely cover the mouth. 748 may be removably mounted to the top of the wall portion 744 to accommodate the lamp components and This allows the user to easily change the brightness and emission color.

[0048] LCD and display backlight Although the above-described white light emitting devices may be described with respect to general lighting applications, the practice of the present invention Devices in this form find utility as backlights for liquid crystal displays. As such, for backlighting applications, MQW LED dies offer narrower FWHM radiant intensity. blue light having a wavelength of, for example, about 15 nm to about 30 nm or about 15 nm to about 25 nm; Similarly, the red photoluminescent material is configured to generate red and / or green light. is a narrowband material (FWHM radiation of about 10 nm to about 30 nm or about 15 nm to about 25 nm). Intensity).

[0049] 8A and 8B are respectively a light-transmitting edge-illuminated color liquid crystal display; FIG. 8 is a cross-sectional view of an LCD 860; and FIG. 9 is a cross-sectional view of a display back according to an embodiment of the present invention. The color LCD860 uses an LC (liquid crystal) display panel. The backlight 864 includes an LC display 862 and a display backlight 864. The LED 862 is operable to generate white light for operating the display panel 862.

[0050] The LC display panel 862 is a transparent (light-transmitting) front (light / image-emitting) plate. 866, transparent backplate 868, and front and backplate 866 , 868 includes a liquid crystal (LC) 870 that fills the volume between the

[0051] The front plate 866 includes a glass plate 872 having a top surface, i.e., A first polarizing filter layer (sheet) 874 is provided on the surface of the plate that includes the display surface of the display. Optionally, the outermost viewing surface of the front plate may have an anti-reflective layer 876. The lower side, i.e., the front plate facing the liquid crystal (LC) 870, may further include a On the side of plate 866, glass plate 872 is connected to color filter plate 878 and and a light-transmitting common electrode plate 880 (e.g., transparent indium tin oxide, ITO). It may further include:

[0052] The color filter plate 878 is a plate for detecting red (R), green (G), and blue ( B) An array of sub-pixel filter elements of different colors R, G, B that allow light transmission. Each unit pixel of the display contains three sub-pixel filter elements R, G, B group, each RGB subpixel corresponds to the subpixel color only Each color filter contains pigments, typically organic dyes, that allow light to pass through.

[0053] The backplate 868 includes a glass plate 882, the top surface of which (the surface facing the LC) ) may have a TFT (thin film transistor) layer 884. The TFT layer 884 may be an array of TFTs. Each unit pixel includes a subpixel R, G, B corresponding to each individual color subpixel. Each TFT selectively controls the passage of light to its corresponding subpixel. The lower surface of the glass plate 882 is operable to control the second polarizing filter. The polarizing filters 874 and 886 are arranged in a polarizing layer (sheet) 886. The directions are aligned orthogonally (perpendicularly) to each other.

[0054] The backlight 864 is a front light source for driving the LC display panel 862. It is designed to generate and emit white light from its light-emitting surface (the upper surface facing the rear of the display panel). As shown in FIG. 8B, the backlight 864 is connected to a light guide 88. One or more packaged MQW dual-wavelength LEDs located along one or more edges of the 8 Each MQ may include an edge lighting arrangement including a light guide 888 having a light guide 20. The 820W LED has a dominant wavelength (λ d1 ) blue The present invention is directed to generate a 500 nm to 540 nm dominant wavelength green light. As shown, the light guide 888 can be planar, although in some implementations In the embodiment, the light guide is provided with a front light emitting surface (upper surface facing the display panel) The LED may be tapered (wedge-shaped) to promote more uniform emission of the excitation light. In operation, 820 is coupled to one or more edges of a light guide 888 and then By total internal reflection, it is guided throughout the volume of the light guide and finally A blue / 8B, and configured to generate green excitation light 890. To prevent light from escaping from the light 864, the rear surface of the light guide 888 (as shown) The underside is made of Vikuiti™ ESR (Enhanced Includes light reflective layers (surfaces) such as Spectral Reflector films obtain.

[0055] The front emitting surface of the light guide 888 (top surface as shown) contains photoluminescent A wavelength converting layer 822 and a brightness enhancement film (BEF) 894 are provided. In the form, the photoluminescent layer is, for example, BEF894 or Lightguide888 According to an embodiment of the present invention, The photoluminescent layer has a peak emission wavelength (λ pe) The photoluminescent material includes a red photoluminescent material that produces red light that is are provided in respective layers 822 separate from and remote to the LEDs 820. Therefore, the backlight is a device in which the excitation source and the photoluminescent material are immersed in the optical medium (light guide). It is understood that this constitutes a remote photoluminescence arrangement, separated by a gate 888. In operation, the photoluminescent layer 822 creates an LC display panel 862. In order to achieve this (in some cases depending on the excitation spectrum of the photoluminescent material) It converts a portion of the blue excitation light (which is also green light) into white light 898. This improves the efficiency and To optimize the color gamut and brightness, the blue light λ d1 and green light λ d2 The dominant wavelength of and Peak emission wavelength λ of red photoluminescent material pe are their corresponding color filters. The transmittance of each of the filter elements RGB is selected to substantially correspond to the maximum transmittance of the filter elements RGB.

[0056] Brightness Enhancement Film (BEF), also known as prism sheet, is a precision micro-structured light It contains an optical film and directs the light emitted from the backlight within a fixed angle (typically 70 degrees). Typically, the BEF is a backlight that controls the light output of the backlight, thereby increasing the luminous efficiency of the backlight. It contains an array of microprisms on the emitting surface of the film, which increases brightness by 40-60%. BEF894 may contain a single BEF or a combination of multiple BEFs. In the latter case, an even greater increase in brightness can be achieved. Examples of F include Vikuiti™ BEF II or MNTec from 3M™. h. In some embodiments, the BEF894 includes a prism sheet. The light source may include a multi-function prism sheet (MFPS) that integrates the light source with a diffusion film, The prism sheet can have a light emitting efficiency superior to that of a normal prism sheet. So, BEF894 is a microlens film such as those available from MNTech. It may include a prism sheet (MLFPS).

[0057] In the above embodiment, the backlight distributes light across the entire area of ​​the display. While the previous example was an edge-illuminated arrangement utilizing a light guide for illumination, various embodiments of the present invention , a direct-lighting backlight in which an array of LEDs is constructed on the surface of an LC display panel. FIG. 9 illustrates a packaged light emitting device 910, e.g., as shown in FIGS. An array of packaged light emitting devices is attached to the floor 910 of a light reflective enclosure 9102. 9 illustrates a direct-lit backlight arrangement 964 mounted on a luminous device. (The light emitting device is mounted on the MCPCB948 shown.) The device 910 may include the packaging arrangement of FIG. To ensure the best image quality, the backlight is fitted with a light-reflective enclosure 9102 and BEF99 4. The optical element may further include a light diffusing layer (diffuser) 9104 disposed between the optical element and the reflector.

[0058] FIG. 10 is a schematic cross-section of a further direct-lit backlight 1064 in accordance with an embodiment of the present invention. In this embodiment, an array of CSP packaged light emitting devices 1010 includes: It is mounted on the MCPCB 1048 on the floor of the light-reflective enclosure 10100. As shown, the light emitting device 1010 may include the CSP packaging arrangement of FIG. The light emitting devices are arranged in an array and cover the entire surface area of ​​the display. To ensure uniform illumination of the panel, the backlight is enclosed in a light-reflective enclosure1 A light diffusing layer (diffuser) 10104 disposed between 0100 and BEF1094 It may further include.

[0059] FIG. 11 is a schematic cross-sectional view of a further direct-lit backlight in accordance with an embodiment of the present invention. In this embodiment, the photoluminescent material is a MQW dual wavelength LED 1120. The MQW dual-wavelength The long LED chip 1120, e.g., an array of LED flip chips, is enclosed in a light reflective enclosure. The MQW dual wavelength LE is mounted on the MCPCB 1148 on the floor of the LE 11102. The D chips 1120 are arranged in an array and cover the entire surface area of ​​the display. As such, the layer of photoluminescent material 1122 is disposed within the light reflective enclosure 111. 02. To ensure uniform illumination of the display panel, The backlight was placed between the photoluminescent layer 1122 and the BEF 1194. It may further include a light diffusing layer (diffuser) 11104. In a separate remote layer 1122 Locating the photoluminescent material in the cavity is particularly advantageous because it is very small. The aim of this project is to enable the use of "micro" LED flip chips that are not otherwise Their small dimensions allow for individual coating of red photoluminescent material. Typically, the dimensions of a micro LED chip are: It is less than 50 μm.

[0060] Red Photoluminescent Material In an embodiment of the present invention, the red photoluminescent material is at least It has an excitable peak at about 620 nm to about 660 nm, which is in the red region of the visible spectrum. Radiation wavelength (λ pe ) operable to emit light having a molecular weight greater than about 5 nm and about 80 Any narrow or broadband red photodiode with a full width at half maximum (FWHM) radiant intensity of less than 1 nm Typically, the red photoluminescent material is a particle. narrow-band manganese-activated fluoride phosphors, narrow-band europium-activated fluoride phosphors, For general lighting, the use of fluorine-activated Group IIA / IIB sulfide selenide phosphors The red phosphor may include a broadband red phosphor such as a ruthenium-activated silicon nitride based phosphor. The photoluminescent material may include a quantum dot material.

[0061] Narrowband red photoluminescent material In this patent specification, a narrow band red photoluminescent material is a material having a wavelength of 620 nm to 640 nm. Peak emission wavelength (λ pe ) and has a full width at half maximum of about 5 nm to about 60 nm. Narrowband red photoluminescent materials are materials that produce red light that emits red light that is narrow band. and / or quantum dot (QD) materials.

[0062] Narrow-band red phosphor: Manganese-activated fluoride phosphor The narrow band red phosphor may include a manganese activated fluoride phosphor. An example of a phosphor is the common composition K2SiF6:Mn 4+ Manganese-activated hexafluorosilicic acid One example of such a phosphor has a peak emission wavelength of about 632 nm. radiation wavelength (λ pe Intematix Corporation, which owns Fremon NR6931 KSF phosphor from California, USA. The emission spectrum of the NR6931 KSF phosphor is shown in Fig. 1. The KSF phosphor is excited by blue light. Therefore, it can be excited, and has a FWHM of about 5 nm to about 10 nm and a wavelength of about 631 nm to about 6 Peak emission wavelength (λ pe ) (Depends on how you measure: i.e. width, length, Consider the main and satellite radiation peaks (double peak, Figure 12) Other manganese activated phosphors include K2Ge F6:Mn 4+ , K2TiF6:Mn 4+ , K2SnF6:Mn 4+ , Na2TiF6: Mn 4+ , Na2ZrF6:Mn 4+ , Cs2SiF6:Mn 4+ , Cs2TiF6:M n 4+ , Rb2SiF6:Mn 4+ , Rb2TiF6:Mn 4+ , K3ZrF7:Mn 4 + , K3NbF7:Mn 4+ , K3TaF7:Mn 4+ , K3GdF6:Mn 4+ , K3 LaF6:Mn 4+ , and K3YF6:Mn 4+ may include.

[0063] Narrow-band red phosphors: Group IIA / IIB sulfide selenide phosphors Narrow band red phosphors can also include Group IIA / IIB sulfide selenide based phosphors. A first example of a Group A / IIB selenide sulfide phosphor material has the general composition MSe 1-x S x : Eu, where M is at least one of Mg, Ca, Sr, Ba, and Zn and 0 < x < 1.0. A specific example of this phosphor material is calcium selenide sulfide " CSS" phosphor (CaSe 1-x S x :Eu). Details of the CSS phosphor are provided in co-pending U.S. Patent Application Publication No. 2017 / 0145309, filed September 30, 2016 , which is hereby incorporated by reference in its entirety. The narrow-band red phosphor of CSS described in U.S. Patent Publication No. 2017 / 0145309 can be used in the present invention. FIG. 13 shows the normalized emission spectra of CSS phosphors ( shown as CSS604, CSS615, CSS624, CSS632, CSS641) for different ratios of S / Se (sulfur / selenium). In this patent specification, the notation CSS# follows the type of phosphor (CSS) and represents the peak emission wavelength (#) in nanometers. For example , CSS624 represents a CSS phosphor having a peak emission wavelength λ of 624 nm. The peak emission wavelength of the C SS phosphor can be adjusted to 600 nm to 650 nm by varying the S / Se ratio in the composition and has a narrow-band red emission spectrum with an FWHM in the range of about 48 nm to about 60 nm (longer peak emission wavelengths typically have larger FWHM values). Note that x varies over the range of about 0.05 to about 0 pe .8 for the compositions shown in FIG. 13. This is a higher peak wavelength corresponding to a larger value of x, i.e., as the amount of S increases, the emission peak is shifted more towards longer wavelengths. towards longer wavelengths. towards longer wavelengths and has a narrow-band red emission spectrum with an FWHM in the range of about 48 nm to about 60 nm (longer peak emission wavelengths typically have larger FWHM values). It should be noted that x varies over the range of about 0.05 to about 0 .8 for the compositions shown in FIG. 13. This is a higher peak wavelength corresponding to a larger value of x, i.e., as the amount of S increases, the emission peak is shifted more towards longer wavelengths. This is a higher peak wavelength corresponding to a larger value of x, i.e., as the amount of S increases, the emission peak is shifted more towards longer wavelengths, that is, a higher peak wavelength corresponding to a larger value of x, i.e., as the amount of S increases, the emission peak is shifted more towards longer wavelengths. Shift to a higher wavelength.

[0064] CSS phosphor particles are made from purified CaSeO4 and CaSO4 in a mild H2 It can be synthesised in a (gaseous) environment (eg, about 5% H2 / N2).

[0065] Narrowband red phosphor: Coated CSS phosphor To improve reliability, the particles of the CSS phosphors may be coated with one or more oxides, e.g. Aluminum (Al2O3), silicon oxide (SiO2), titanium oxide (TiO2), oxide Zinc oxide (ZnO), magnesium oxide (MgO), zirconium oxide (ZrO2), porphyrin oxide Can be coated with borane (B2O3) or chromium oxide (CrO) Alternatively and / or additionally, the particles of the narrow band red phosphor may be one or more fluorides (f louride), e.g. calcium fluoride (CaF2), magnesium fluoride (Mg F2), zinc fluoride (ZnF2), aluminum fluoride (AlF3) or titanium fluoride (TiF4). The coating may be a single layer or the above The combination coating may be a multi-layer coating having a combination of coatings. It may be a coating having an abrupt transition between the first material and the second material, or It may be a coating in which there is a gradual / smooth transition from one material to a second material, This creates a zone of mixed composition that varies through the thickness of the coating.

[0066] For details of the CSS phosphor particles to be coated, see the US Patent Publication dated April 9, 2019. No. 10,253,257, the entirety of which is incorporated herein by reference. As described in US 10,253,257, the particles are mixed in a CV reactor in a fluidized bed reactor. It can be coated by the D process. The coating thickness is several microns. For example, it is typically 1 μm to 2 μm.

[0067] The coated CSS narrowband red phosphor is typically made of amorphous aluminum of about 1 μm thickness. In the case of alumina coating, the coating The coating is pinhole-free, i.e., water-impermeable. The CSS phosphor contains a dense amorphous oxide coating layer on the particle surface, which is free of adhesion. .

[0068] In a typical coating process, the phosphor powder sample is loaded into a reactor and heated with N2 gas. Heat under high pressure to 100-250°C, preferably 200°C. An oxide coating is deposited. When used, trimethylaluminum (TMA), titanium tetrachloride (TiCl4), Silicon (SiCl4) or metal organic oxide precursors such as dimethylzinc (DMZ) The H2O vapor was introduced into the reactor through an inlet by N2 carrier gas via a bubbler. Gas may also be introduced into the reactor through an additional inlet to react with the metal oxide precursor and produce fluorescent An oxide coating layer was formed on the phosphor particles. To ensure proper cooling, there must be no dead space and the cooling must be optimized (e.g., from gas flow optimization). It is important to completely fluidize the particles being coated. In a typical coating carried out at 200°C on a reactor packed with particles, the coating The rings were generated by metal oxide precursors at feed rates of 1–10 g / h for 4 h and H 2O was fed at a rate of 2 to 7 g / h. Under these conditions, high density and pinhole-free These conditions produce coatings with 95%, 97%, and 99% %. It is possible to produce dense, virtually pinhole-free coatings of uniform thickness. In this patent specification, the percentage of solid space = (bulk density of coating / single The density of the material in one particle is multiplied by 100. The percentage of solid space (% solid space) is It will be appreciated that this provides a measure of the porosity of the coating resulting from pinholes. .

[0069] Narrowband red photoluminescent material: Red quantum dots (QDs) Quantum dots (QDs) are electrons whose excitons are excited by radiation energy and emit specific wavelengths. Capable of emitting light in a long or wavelength range, confined in all three spatial dimensions The color of light produced by a QD depends on the nanoparticles in the QD. This is possible due to the quantum confinement effect associated with the nanocrystal structure. The energy levels of each QD are is directly related to the physical size of the QDs. For example, larger QDs, such as red QDs, have Absorbing and emitting photons with relatively low energy (i.e., relatively long wavelengths) On the other hand, blue QDs, which are smaller in size, emit relatively high energy (shorter wavelengths). ) photons. QDs have a FWHM emission range of 20 nm to 45 nm. Produces light having an intensity.

[0070] QD materials may include core / shell nanocrystals that contain different materials in an onion-like structure. For example, the exemplary materials described above may be used as core materials for core / shell nanocrystals. The optical properties of a core nanocrystal in one material can be compared to the epitaxial shell of another material. Depending on the requirements, the core / shell nanoparticles can be grown in a variety of ways. The crystals can have a single shell or multiple shells. The shell material is the band gap element. For example, the shell material may be selected based on engineering. They can have large bandgaps, which makes the shell of the nanocrystals optically active. The surface of the cadmium-based QDs, e.g., C For dSe QDs, the core / shell quantum dots are CdSe / ZnS, CdSe / CdS , CdSe / ZnSe, CdSe / CdS / ZnS, or CdSe / ZnSe / ZnS Similarly, CuInS2 quantum dots can be synthesized using the formula The shell / shell nanocrystals are CuInS2 / ZnS, CuInS2 / CdS, and CuInS2 / It can be synthesized using the formula CuGaS2, CuInS2 / CuGaS2 / ZnS, etc. can.

[0071] The QDs can comprise different materials, and examples of red QD compositions are shown in Table 1. [Table 1]

[0072] Figure 14. Measured radiation intensity vs. wavelength for an MQW dual-wavelength LED for color LCDs. The MQW dual-wavelength LED contains multiple blue and green quantum wells and emits approximately 45 Dominant wavelength (λ d1 ) and blue light with a FWHM of about 18 nm 1411 0, with a dominant wavelength (λ d2 ) and has a FWHM of approximately 30 nm. The ratio of peak radiant intensity of green radiation to blue radiation, That is, the ratio of the peak radiant intensity of the green radiation peak to the peak radiant intensity of the blue radiation peak. The measured test data shows that the green to blue ratio is 30% to 60%. The ratio of the peak radiant intensity of the radiation is at least 30%, at least 40%, at least 50% , at least 60%, 30%~50%, 30%~40%, 40%~50%, 40%~60 %, or 50% to 60%, but at least 30%, at least 40%, It is demonstrated that the ratio of the specific disks is 50% and typically 30% to 50%. Specific white color points for pre-color filters (red, green, and blue filters) To meet NTSC targets, the dominant wavelengths of blue and green radiation are The green emission versus blue emission can be adjusted by the indium doping concentration in the N-layer. The ratio of the peak intensities can be adjusted by the number and position of the quantum wells in the MQW structure. Cut.

[0073] FIG. 15. MQW dual-wavelength LED of FIG. 14 and narrow-band manganese-activated KSF phosphor Batteries according to embodiments of the present invention include SMD packages (e.g., the package of FIG. 1) that include Measured radiation spectrum, intensity vs. wavelength, for a kryte. In this particular example, the color gamut is , CIE (0.277, 0.243) white color point, NTSC RGB color space standard surface Further test results show that the barrier formed in accordance with the present invention is The backlight has a color gamut that is at least 90% of the area of ​​the DCI-P3 RGB color space standard. It is shown that it is possible to generate light having the above properties.

[0074] Light emitting devices for general lighting applications The present invention finds particular utility for backlighting applications for color LCDs, The utility can also be extended to general lighting applications, e.g. QW dual-wavelength LEDs have a dominant wavelength of 500nm to 560nm and a wider FW HM radiation intensity, for example, from about 15 nm to about 60 nm, from about 25 nm to about 60 nm, or from about 4 It can be configured to generate blue and / or green light having a wavelength between 5 nm and about 60 nm. In general lighting applications, for example, red photoluminescent materials have wavelengths between 600 nm and 66 0 nm, which is in the orange to red range of the visible spectrum. In typical lighting applications, for example, photoluminescent materials have broadband It may contain red photoluminescent material. Broadband red photoluminescent material (fluorescent Examples of broadband red photoluminescent materials are shown in Table 2. The material contains a europium-activated silicon nitride-based red phosphor, and has the general formula CaAlSiN3:Eu 2+ Calcium aluminum silicon nitride phosphor (CASN) , doped with other elements such as strontium (Sr), and has the general formula (Sr,Ca)AlSi N3:Eu 2+ (SCASN). The CASN phosphor has a wavelength of about 620 nm to Peak emission wavelength (λ pe ) and has a full width at half maximum of about 70 nm to about 80 nm It has a radiant intensity.

[0075] In one embodiment, the red phosphor is “Red-Emitting Nitride-Ba sed Calcium-Stabilized Phosphors" The phosphor may include a red-emitting phosphor as taught in U.S. Pat. No. 8,597,545. Such red-emitting phosphors have the formula M a Sr b S c Al d N e EU f In the formula, M is Ca, and 0.1≦ a ≤ 0.4; 1.5 <b<2.5;4.0≦c≦5.0;0.1≦d≦0.15;7.5 <e<8.5;および0<f<0.1、ここで、a+b+f> 2+d / v, and v is is the valence of M.

[0076] Alternatively, the red phosphor may be referred to as "Red-Emitting Nitride-Based As taught in U.S. Pat. No. 8,663,502 entitled "Phosphors" The nitride-based compositions include red-emitting nitride-based phosphors, which are incorporated herein in their entirety. Such red-emitting phosphors include those having the formula M (x / v) M'2Si 5-x Al x N8:R E, where M is at least one monovalent, divalent, or trivalent gold atom having a valence v. M' is at least one of Mg, Ca, Sr, Ba, and Zn. , RE is at least one of Eu, Ce, Tb, Pr, and Mn, and x is The red-emitting phosphor satisfies 0.1≦x<0.4 and has a general crystal structure of M′2Si5N8:RE. wherein Al is substituted for Si in the general crystal structure and M is substantially a lattice An example of such a red nitride phosphor is Int ematix Corporation, Fremont California, US A is a phosphor of the XR series. [Table 2]

Claims

1. a multiple quantum well dual wavelength LED; A narrowband photodiode that produces red light having a peak emission wavelength of about 620 nm to about 660 nm. A luminescent material; 1. A white light emitting device comprising: At least one first quantum well that produces blue light having a dominant wavelength of 470 nm. and at least one optical fiber that generates green light having a dominant wavelength of 520 nm to 540 nm. a second quantum well.

2. The multi-quantum well dual-wavelength LED comprises a plurality of first quantum wells and a plurality of second quantum wells. The lighting device of claim 1 , further comprising a door.

3. the blue and green lights have a full width at half maximum radiant intensity of about 15 nm to about 45 nm; 10. The light emitting device of claim 1.

4. At least one of the blue light and the green light has a full-width at half maximum (FWHM) of about 25 nm to about 45 nm. The light emitting device of claim 1 having a radiant intensity of a range.

5. At least one of the blue light and the green light has a full wavelength at half maximum (FWHM) of about 15 nm to about 25 nm. The light emitting device of claim 1 having a radiant intensity of a range.

6. 4. The method of claim 3, wherein the narrow band photoluminescent material comprises a manganese activated fluoride phosphor.

2. The light emitting device according to claim 1.

7. The manganese-activated fluoride phosphor is ２ SiF ６ : Mn ４＋ , K ２ TiF ６ : Mn ４ ＋ , and K ２ GeF ６ : Mn ４＋ The invention according to claim 6, comprising at least one of Optical devices.

8. The narrow band photoluminescent material comprises a europium activated sulfide phosphor.

2. The light emitting device of claim 1.

9. The europium-activated selenium sulfide phosphor is MSe １－ｘ S ｘ : General composition based on Eu wherein M is at least one of Mg, Ca, Sr, Ba, and Zn; 9. The light emitting device of claim 8, wherein 0<x<1.

0.

10. 10. The laser of claim 1 , wherein the narrow band photoluminescent material comprises a quantum dot material. Optical devices.

11. The quantum dot material is cadmium selenium sulfide, CdSeS, and indium phosphide, I 11. The light emitting device of claim 10, wherein said first and second n-type semiconductor layers are selected from the group consisting of nP.

12. The narrow band photoluminescent material is disposed on the multiple quantum well dual wavelength LED. The light-emitting device according to any one of claims 1 to 11,

13. The narrow band photoluminescent material is located far from the multi-quantum well dual wavelength LED. The method according to any one of claims 1 to 11, further comprising spaced apart photoluminescent layers. Light emitting device.

14. The narrow band photoluminescent material is incorporated in an optically transmissive medium.

14. A light emitting device according to any one of claims 1 to 13.

15. 2. The optically transparent medium of claim 1, wherein the optically transparent medium comprises dimethyl silicone or phenyl silicone.

5. The light-emitting device according to claim 4.

16. The narrow band photoluminescent material comprises a manganese activated fluoride phosphor, The device supports at least 90% of the NTSC RGB color space standard and DCI-P3 RGB. A spectrum having a color gamut that is at least 90% of the B color space standard.

13. The light emitting device of claim 1 , producing light having a

17. The blue light and the green light include respective peaks, and the peak emission of the blue light a ratio of the peak radiant intensity of the green light to the radiant intensity of the green light is between 30% and 60%.

2. The light emitting device according to claim 1.

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