White light backlight source adopting blue-green double-peak single crystal chip

Abstract

The utility model relates to the technical field of semiconductor photoelectronics, and provides a white light backlight source adopting a blue-green double-peak single crystal chip, which comprises a packaging structure and an LED chip arranged in the packaging structure. The LED chip comprises a substrate, a blue-green double-peak single-crystal chip and a red light conversion layer which are sequentially stacked from bottom to top, the blue-green double-peak single-crystal chip comprises a short-wavelength blue light gallium nitride layer for electrically emitting blue light and a green light conversion layer for photoluminescence, and the red light conversion layer comprises a red light fluoride phosphor or a red light composite fluoride phosphor. The short-wavelength blue light gallium nitride layer and the green light conversion layer of the LED chip form an integrated structure, the LED chip can simultaneously emit blue light and green light with blue and green peaks under the driving of current, when the LED chip is used as a backlight source, the spatial distribution of the short-wavelength blue light gallium nitride layer and the green light conversion layer is uniform, the risk of blue and green spots is greatly reduced, and the service life of the LED chip is prolonged. And the probability of generating color drift is reduced, so that the color gamut of the LED chip is improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor optoelectronic technology, and more specifically, to a white light backlight source using a blue-green dual-peak single crystal chip. Background Art

[0002] LED combines the advantages of low power consumption, high brightness, high resolution, high color saturation, fast response speed, long life, and high efficiency, and is widely used in the field of display technology. Among them, the mini-LED combined with a new driving and power management method as a backlight source technology for local dimming is adopted by the liquid crystal display industry and realizes a higher dynamic range (HDR), which is widely regarded as the next major trend in the field of display technology.

[0003] However, in order to achieve a wide color gamut backlight display, more pure and narrower full-width at half-maximum of the three primary colors of red, green, and blue are required. Among them, the commonly used method is a blue chip plus narrow-peak-width red and green phosphors. However, due to limited selection of narrow-peak-width green powder materials, there are limitations in wavelength, reliability, cost, etc.

[0004] Another solution is to adopt a packaging form of a separated blue chip and a green chip, combined with a red phosphor. When making a backlight source with a lens, this solution is prone to uneven spatial distribution and the appearance of blue-green spots; in addition, during use, as the two chips have different peak shifts with temperature changes or during use, color point offsets will also occur, especially during the aging process, color drift is more likely to occur.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a white light backlight source using a blue-green dual-peak single crystal chip to solve the technical problems of low color gamut, uneven light color distribution, easy appearance of color difference and color drift of the LED white light source in the existing technology.

[0007] To achieve the above purpose, the utility model provides a white light backlight source using a blue-green dual-peak single crystal chip, including a packaging structure and an LED chip arranged in the packaging structure;

[0008] The LED chip includes a substrate, a blue-green dual-peak single crystal chip, and a red light conversion layer stacked in sequence from bottom to top. The blue-green dual-peak single crystal chip includes a short-wavelength blue gallium nitride layer that emits blue light by electroluminescence and a green light conversion layer that emits light by photoluminescence. The red light conversion layer contains a red fluoride phosphor or a red composite fluoride phosphor.

[0009] Further, the red light conversion layer is a thin film layer stacked on the blue-green dual-peak single crystal chip, or the red light conversion layer is coated on the surface of the blue-green dual-peak single crystal chip.

[0010] In some embodiments, it further includes an organic carrier surrounding the red light conversion layer. The red light fluoride phosphor or the red light composite fluoride phosphor is dispersed in the organic carrier. The organic carrier includes any one or a combination of optical silica gel and optical epoxy glue. The thickness of the red light conversion layer above the blue-green dual-peak chip is 25 - 500 microns.

[0011] Further, the blue and green light emitted by the blue-green dual-peak single crystal chip is directed towards the red light conversion layer, so that the red light wavelength conversion material emits red light.

[0012] Further, the packaging structure includes a lens and a circuit board, and the lens packages the LED chip on the circuit board.

[0013] The beneficial effects of the white backlight source using a blue-green dual-peak single crystal chip and its preparation method provided by the present utility model are at least as follows: By directly growing a short-wavelength blue gallium nitride layer that emits blue light electro-optically and a green light conversion layer that emits green light photo-optically on the gallium nitride layer, which forms an integrated structure. The LED chip can simultaneously emit blue and green light with blue-green dual peaks when driven by current. Compared with the conventional technology that requires separately setting a blue light chip and a green light chip, it avoids the problem of integrating and transferring multiple-color micro LEDs. The preparation process is simple and easy to produce. Moreover, when used as a backlight source, the spatial distribution of the short-wavelength blue gallium nitride layer that emits blue light electro-optically and the green light conversion layer that emits green light photo-optically is uniform, greatly reducing the risk of blue and green spots. During use, as the LED chip does not produce color point shift with temperature change, the probability of color drift is reduced, thereby improving the color gamut of the LED chip. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic structural diagram of a white backlight source using a blue-green dual-peak single crystal chip provided by an embodiment of the present utility model;

[0016] Figure 2 It is another schematic structural diagram of a white backlight source using a blue-green dual-peak single crystal chip provided by an embodiment of the present utility model;

[0017] Figure 3 A schematic structural diagram of an LED chip provided by an embodiment of the present invention;

[0018] Figure 4 Another schematic structural diagram of an LED chip provided by an embodiment of the present invention;

[0019] Figure 5 A schematic diagram showing the display color gamuts of two displays provided by an embodiment of the present invention and the NTSC and BT.2020 standard color gamuts;

[0020] Figure 6 A schematic structural diagram of the LED chip provided by an embodiment of the present invention after being encapsulated by SMD;

[0021] Figure 7 A schematic structural diagram of a blue-green dual-peak single-crystal chip provided by an embodiment of the present invention.

[0022] Among them, the reference numerals in the figure:

[0023] 1. Substrate;

[0024] 2. Blue-green dual-peak single-crystal chip; 21. Short-wavelength blue-light gallium nitride layer; 22. Green-light conversion layer; 23. n-type gallium nitride layer; 24. Isolation layer; 25. Through hole; 26. Insulating layer;

[0025] 3. Red-light conversion layer; 31. Red fluoride phosphor; 32. Red composite fluoride phosphor;

[0026] 4. p-type gallium nitride layer;

[0027] 5. n-type electrode;

[0028] 6. p-type electrode;

[0029] 7. Lens;

[0030] 8. Circuit board;

[0031] 9. First bracket; 91. Second bracket; 92. Gap; 93. Placing groove; 94. Gold wire; 95. Silicone layer. Detailed implementation manners

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly or indirectly located on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component. The orientations or positions indicated by the terms "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positions shown in the drawings, and are only for convenience of description and should not be construed as limiting the technical solution of the present application. The terms "first" and "second" are only used for convenience of description and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. The meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0034] An embodiment of the present utility model provides a white light backlight source using a blue-green dual-peak single crystal chip. The white light backlight source using a blue-green dual-peak single crystal chip according to the embodiment of the present utility model will be described below with reference to the accompanying drawings.

[0035] Please refer to Figure 1 , Figure 1 which shows a schematic structural diagram of a white light backlight source using a blue-green dual-peak single crystal chip of the present application, including a packaging structure and an LED chip disposed in the packaging structure. After the LED chip is excited, the white light backlight source emits white light.

[0036] Specifically, referring to Figures 1-4 and Figure 7 , the LED chip includes a substrate 1, a blue-green dual-peak single crystal chip 2, and a red light conversion layer 3 stacked in sequence from bottom to top. The blue-green dual-peak single crystal chip 2 includes a short-wavelength blue gallium nitride layer 21 that emits blue light electro-optically and a green light conversion layer 22 that emits green light photo-optically. Specifically, it includes a gallium nitride layer and a short-wavelength blue gallium nitride layer 21 that emits blue light electro-optically and a green light conversion layer 22 that emits green light photo-optically epitaxially grown on the gallium nitride layer. The red light conversion layer 3 contains a red fluoride phosphor 31 or a red composite fluoride phosphor 32.

[0037] From the perspective of product implementation, by controlling the growth conditions of the quantum well layer, a short-wavelength blue gallium nitride layer 21 that emits blue light electro-optically and a green light conversion layer 22 that emits green light photo-optically are directly integrated on the gallium nitride layer, and then the red light conversion layer 3 is stacked on the blue-green dual-peak single crystal chip 2. Specifically, it is stacked on the green light conversion layer 22. The blue light emitted by the short-wavelength blue gallium nitride layer 21 and the green light excited by the green light conversion layer 22 are used to excite the red fluoride phosphor 31 or the red composite fluoride phosphor 32 in the red light conversion layer 3 to emit red light, obtaining a red light emitting unit, thereby integrating RGB pixel units to achieve full-color display.

[0038] Among them, in the present application, a short-wavelength blue gallium nitride layer 21 and a green light conversion layer 22 are directly integrated on a gallium nitride layer to form a blue-green dual-peak single-crystal chip 2 with an integrated structure. When the LED chip is driven by current, it can emit blue light and green light with blue-green dual peaks simultaneously. Compared with the conventional technology that requires separately setting a blue light chip and a green light chip, it avoids the problem of integrating and transferring multiple-color micro-LEDs, has a simple preparation process, is easy to produce, and, when used as a backlight source, the spatial distribution of the short-wavelength blue gallium nitride layer 21 and the green light conversion layer 22 is uniform, greatly reducing the risk of blue and green spots. During normal use, as the LED chip is more difficult to generate color point shift with temperature change, the probability of generating color drift is reduced, thereby improving the color gamut of the LED chip.

[0039] Further, the red fluoride phosphor 31 includes at least one phosphor selected from the group consisting of:

[0040] (A) A2[MF5]:Mn 4+ , where A is selected from Li, Na, K, Rb, Cs, NH4, and combinations thereof; and M is selected from Al, Ga, In, or combinations thereof;

[0041] (B) A3[MF6]:Mn 4+ , where A is selected from Li, Na, K, Rb, Cs, NH4, and combinations thereof; and M is selected from Al, Ga, In, or combinations thereof;

[0042] (C) Zn2[MF7]:Mn 4+， where M is selected from Al, Ga, In, or combinations thereof; and

[0043] (D) A[In2F7]:Mn 4+ , where A is selected from Li, Na, K, Rb, Cs, NH4, or combinations thereof.

[0044] Further, the red light conversion layer 3 is a thin film layer stacked on the blue-green dual-peak single-crystal chip 2, or the red light conversion layer is coated on the surface of the blue-green dual-peak single-crystal chip 2; the LED chip further includes an organic carrier surrounding the red light conversion layer 3, and the red fluoride phosphor 31, the red composite fluoride phosphor 32, or the other phosphor is dispersed in the organic carrier. The organic carrier includes any one or a combination of optical silica gel and optical epoxy glue, and the thickness of the red light conversion layer above the blue-green dual-peak chip is 25 - 500 microns.

[0045] Specifically, after dilution with an inorganic solvent such as acetone, MIBK or butyl acetate, a slurry in which the red fluoride phosphor 31 or the red composite fluoride phosphor 32 particles are randomly suspended and located around the LED can be manufactured using silicone resin, epoxy resin or other matrix materials. It should be noted that this is only an example of the possible positions of the phosphor material and the LED.

[0046] Therefore, the red fluoride phosphor 31 or the red composite fluoride phosphor 32 can be coated on the green light conversion layer 22 of the LED chip by coating the phosphor suspension on the LED chip and drying or curing it.

[0047] Furthermore, the red light conversion layer 3 further includes one or more other phosphors, and the one or more other phosphors are fluorosilicates excited by tetravalent manganese (with the molecular formula AxMFy:Mn 4+ fluoride KSF or KGF), or Ce 3+ activated garnet, or one or more of alkaline earth metal orthosilicates activated by Eu 2+ , and of course, it can also be a nitride red phosphor.

[0048] Specifically, it may include but is not limited to the following materials:

[0049] (Ba, Sr, Ca)5(PO4)3(Cl, F, Br, OH):Eu 2+ , Mn 2+ ; (Ba, Sr, Ca)BPO5:Eu 2+ , Mn 2+ ;

[0050] (Sr, Ca) 10 (PO4)6*vB2O3:Eu 2+ , where 0 < v ≤ 1; Sr2Si3O8*2SrCl2:Eu 2+ ;

[0051] (Ca, Sr, Ba)3MgSi2O8:Eu 2+ , Mn 2+ ;

[0052] BaAl8O13:Eu 2+ ;

[0053] 2SrO*0.84P2O5*0.16B2O3:Eu 2+ ;

[0054] (Ba, Sr, Ca)MgAl 10 O 17 :Eu 2+ , Mn 2+ ;

[0055] (Ba, Sr, Ca)Al2O4:Eu 2+ 。

[0056] Furthermore, the blue and green light emitted by the blue-green dual-peak single crystal chip is directed towards the red light conversion layer, so that the red light wavelength conversion material emits red light.

[0057] In some embodiments, based on this red light conversion layer 3, combined with other perovskite quantum dots or other red light quantum dots, a backlight source with a high color gamut can be obtained under the excitation of blue light and green light.

[0058] Exemplarily, a red light fluoride phosphor 31 or a red light composite fluoride phosphor 32 combined with perovskite quantum dots or other red light quantum dots constitutes the red light conversion layer 3, and its displayed color gamut can reach 113% of the NTSC color gamut.

[0059] Of course, other red light quantum dots can be any one or a combination of red light wavelength conversion materials such as cadmium selenide quantum dots, lead selenide quantum dots, mercury antimonide quantum dots, and lead sulfide quantum dots.

[0060] In some embodiments, the blue-green dual-peak single crystal chip 2 grows InxGa1-xN / GaN quantum well layers on both the polar and non-polar surfaces of the patterned n-type gallium nitride layer 23.

[0061] The InxGa1-xN / GaN quantum well layer grown on the polar surface serves as a green light conversion layer 22 that emits green light under photoexcitation, with an x value of 0.15 - 0.35. The InxGa1-xN / GaN quantum well layer grown on the non-polar surface serves as a short-wavelength blue light gallium nitride layer 21 that emits blue light under electroexcitation, with an x value of 0.15 - 0.35.

[0062] Specifically, the well layer and barrier layer of the green light conversion layer 22 have thicknesses of 2 - 9 nanometers and 9 - 20 nanometers respectively, and the well layer and barrier layer of the short-wavelength blue light gallium nitride layer 21 have thicknesses of 1 - 6 nanometers and 9 - 20 nanometers respectively.

[0063] At the material growth level, by simultaneously growing quantum well layers (InxGa1-xN / GaN, x = 0.15 - 0.35) on the polar and non-polar surfaces of the n-type gallium nitride layer 23, the quantum well layer epitaxially grown on the polar surface emits green light after blue light is incident, serving as the green light conversion layer 22. The growth rate of the quantum well layer epitaxially grown on the non-polar surface is lower than that of the polar surface, and the well width of the epitaxial quantum well becomes narrower, resulting in a blue shift of its emission wavelength and emitting blue light after electroexcitation, serving as the short-wavelength blue light gallium nitride layer 21 that emits blue light under electroexcitation. By controlling the growth conditions of the quantum well active layer, the short-wavelength blue light gallium nitride layer 21 and the green light conversion layer 22 are directly integrated.

[0064] It should be noted that in this application, the short-wavelength blue light gallium nitride layer 21 is electroluminescent, and the green light conversion layer 22 and the red light conversion layer 3 are photoluminescent. The complete color conversion uses the short-wavelength blue light gallium nitride layer 21 as the excitation source. After an electric current is applied to the short-wavelength blue light gallium nitride layer 21, blue light is emitted. After the blue light enters the green light conversion layer 22, a part of the blue light excites the green light conversion layer 22 to emit green light, and a part of the blue light passes through the green light conversion layer 22 and irradiates into the red light conversion layer 3, pumping the red light wavelength conversion material including the perovskite quantum dots 31 in the red light conversion layer 3 to emit red light. By using the color conversion strategy, the required green light and red light emissions are obtained, which are combined with the blue light emitted by the short-wavelength blue light gallium nitride layer 21 to produce white light, realizing full-color backlight display.

[0065] Furthermore, the short-wavelength blue light gallium nitride layer 21 for photoluminescence is composed of indium gallium nitride material or a composite material with indium gallium nitride, and the green light conversion layer 22 for photoluminescence is composed of any one of gallium aluminum phosphide, indium gallium nitride / gallium nitride, gallium phosphide, indium gallium aluminum phosphide, gallium carbide or a combination thereof.

[0066] Furthermore, referring to Figures 2-4 , the short-wavelength blue light gallium nitride layer 21 and the red light conversion layer 3 continue to grow epitaxially to form a p-type gallium nitride layer 4. An n-type electrode 5 is deposited on the n-type gallium nitride layer 23, and a p-type electrode 6 is deposited on the p-type gallium nitride layer 4.

[0067] Among them, referring to Figures 2-4 , the n-type electrode 5 deposited on the n-type gallium nitride layer 23 is used to be electrically connected to the circuit board, and the p-type electrode 6 deposited on the p-type gallium nitride layer 4 grown epitaxially on the short-wavelength blue light gallium nitride layer 21 is used to be electrically connected to the circuit board, so that the circuit board supplies power to the electroluminescent short-wavelength blue light gallium nitride layer 21.

[0068] In the above embodiment, the short-wavelength blue light gallium nitride layer 21 is located between the substrate 1 and the green light conversion layer 22. In some embodiments, referring to Figure 1 and Figure 7, the green light conversion layer 22 is disposed between the substrate 1 and the short-wavelength blue gallium nitride layer 21. Specifically, from the substrate 1 upwards, there are the green light conversion layer 22, the short-wavelength blue gallium nitride layer 21, and the red light conversion layer 3 in sequence. Among them, the short-wavelength blue gallium nitride layer 21 is the electroluminescent region, and both the green light conversion layer 22 and the red light conversion layer 3 are the photoluminescent regions. The complete color conversion uses the short-wavelength blue gallium nitride layer 21 as the excitation source. After current is applied to the short-wavelength blue gallium nitride layer 21, blue light is emitted. A part of the blue light enters the green light conversion layer 22 and excites the green light conversion layer 22 to emit green light. Another part of the blue light irradiates the red light conversion layer 3, pumping the red light wavelength conversion material including the red fluoride phosphor 31 or the red composite fluoride phosphor 32 in the red light conversion layer 3 to emit red light. By adopting the color conversion strategy, the required green light and red light emissions are obtained, which are combined with the blue light emitted by the short-wavelength blue gallium nitride layer 21 to produce white light, realizing full-color backlight display.

[0069] Further, continue to refer to Figure 1 and Figure 7 , the blue-green dual-peak single crystal chip 2 includes a gallium nitride layer. The gallium nitride layer includes an n-type gallium nitride layer 23 and a p-type gallium nitride layer 4. The blue-green dual-peak single crystal chip 2 grows an InxGa1-xN / GaN quantum well layer on the polar surface of the patterned n-type gallium nitride layer 23 as the green light conversion layer 22 that emits green light by photoluminescence. The value of x is 0.15 - 0.35. The non-polar surface of the n-type gallium nitride layer 23 is disposed on the substrate 1. Then, an isolation layer 24 is disposed on the green light conversion layer 22, and an InxGa1-xN / GaN quantum well layer is grown on the isolation layer as the short-wavelength blue gallium nitride layer 21 that emits blue light by electroluminescence. The value of x is 0.15 - 0.35. Then, a p-type gallium nitride layer 4 is epitaxially grown on the short-wavelength blue gallium nitride layer 21 to form the blue-green dual-peak single crystal chip 2. Specifically, the thicknesses of the well layer and the barrier layer of the green light conversion layer 22 are 2 - 9 nanometers and 9 - 20 nanometers respectively, and the thicknesses of the well layer and the barrier layer of the short-wavelength blue gallium nitride layer 21 are 1 - 6 nanometers and 9 - 20 nanometers respectively.

[0070] Among them, continue to refer to Figure 1 and Figure 7, an n-type electrode 5 is deposited on the n-type gallium nitride layer 23, and a p-type electrode 6 is deposited on the p-type gallium nitride layer 4. The n-type electrode 5 deposited on the n-type gallium nitride layer 23 is used for electrical connection with a circuit board. A through hole 25 is etched on the isolation layer 24 and the green light conversion layer 22. The two ends of the through hole 25 are respectively communicated with the n-type gallium nitride layer 23 and the short-wavelength blue light gallium nitride layer 21. The n-type gallium nitride layer 23 and the short-wavelength blue light gallium nitride layer 21 are electrically connected by a wire. An insulating layer 26 is arranged on the inner wall of the through hole 25 to prevent the wire between the n-type gallium nitride layer 23 and the short-wavelength blue light gallium nitride layer 21 from being energized with other structural layers. The p-type electrode 6 deposited on the p-type gallium nitride layer 4 epitaxially grown on the short-wavelength blue light gallium nitride layer 21 is used for electrical connection with the circuit board 8. Thus, the circuit board 8 supplies power to the short-wavelength blue light gallium nitride layer 21 that emits electroluminescence.

[0071] Refer to Figure 1 , for Figure 7 a schematic structural diagram after encapsulation of the blue-green dual-peak single crystal chip 2 in Figure 6 . Of course, other encapsulation methods can also be used to encapsulate the blue-green dual-peak single crystal chip 2 in

[0072] In some embodiments, refer to Figure 2 , the encapsulation structure includes a lens 7 and a circuit board 8. The lens 7 encapsulates the LED chip on the circuit board 8 by means of SMD encapsulation. Specifically, after the LED chip is soldered on the circuit board 8, the LED chip is sealed on the circuit board 8 through the lens 7.

[0073] The display performance of the finally obtained LED chip was characterized. The color performance of the LED chip of the present application is very pure, and the color performance is better than that of the splicing chip that still uses conventional independent blue LED chips and green LED chips. Refer to Figure 5 , for a full-color display based on a conventional LED chip, its display color gamut can only reach 98% NTSC, while for a full-color display based on the LED chip of the present application, the display color gamut is as high as 110% NTSC.

[0074] Among them, when encapsulating the LED chip by means of SMT encapsulation to obtain an SMD package body, it can be carried out as Figure 6in the manner shown. When preparing the LED chip, the step of preparing the red light conversion layer 3 is reduced. During packaging, a silica gel layer is provided on the surface of the LED chip. The red light conversion layer is formed by arranging a red fluoride phosphor 31 and a red composite fluoride phosphor 32 in the silica gel layer. Specifically, a bracket is provided on the circuit board. The bracket includes a first bracket 9 and a second bracket 91 that are butt-jointed. A gap 92 that penetrates to the circuit board 8 is formed between the butt-jointed first bracket 9 and second bracket 91. Moreover, the butt-jointed first bracket 9 and second bracket 91 form a bowl-shaped placement groove 93. A gold wire 94 is provided at the bottom of the placement groove 93. The gold wire 94 is connected to the circuit board 8 through the gap 92. The LED chip is arranged at the bottom of the placement groove 93. The n-type electrode 5 and the p-type electrode 6 are connected to the gold wire 94 to be electrically connected to the circuit board 8. The gap 92 is filled and sealed with a silica gel material, and the first bracket 9 and the second bracket 91 are bonded into an integral structure. The top area of the placement groove 93 is filled with a silica gel layer 95. The red fluoride phosphor 31 and the red composite fluoride phosphor 32 are arranged in the silica gel layer 95.

[0075] An embodiment of the present invention further provides a method for preparing a white backlight source, which is applied to the white backlight source using a blue-green dual-peak single-crystal chip in the above embodiment, and includes the following steps:

[0076] Step 1: Grow an n-type gallium nitride layer 23 on the surface of the substrate 1, perform photolithography on the n-type gallium nitride layer 23 to obtain a patterned n-type gallium nitride layer 23, and form micron grooves with a depth of 500 - 2500 nanometers, a length of 5 - 50 microns, a width of 0.5 - 10 microns, and a pitch of 20 - 200 microns;

[0077] Step 2: Use the MOCVD method to simultaneously grow a quantum well layer (InGaN / GaN quantum well structure) on the polar and non-polar surfaces of the patterned n-type gallium nitride layer 23 to obtain a short-wavelength blue gallium nitride layer 21 and a green light conversion layer 22;

[0078] Step 3: Form the red light conversion layer 3 on the green light conversion layer 22 by means of growth superposition or coating;

[0079] Step 4: Use the MOCVD method to continue epitaxially grow a p-type gallium nitride layer 4 on the short-wavelength blue gallium nitride layer 21 and the red light conversion layer 3;

[0080] Step 5: Etch the LED mesa using ICP-RIE technology. On one side of the LED chip, etch from the top of the p-type gallium nitride layer 4 above the red light conversion layer 3 to the upper surface of the p-type gallium nitride layer 4 below the short-wavelength blue light gallium nitride layer 21. On the other side of the LED chip, etch from the top of the p-type gallium nitride layer 4 above the red light conversion layer 3 to the upper surface of the n-type gallium nitride layer 23. Use the PECVD method to deposit a silicon dioxide insulating layer on the top of the p-type gallium nitride layer 4, the top of the n-type gallium nitride layer 23, and the vertical connection surface between the two, and open holes on the top of the n-type gallium nitride layer 23 (the holes are used to form the n-type electrode 5) and on the top of the p-type gallium nitride layer 4 (the holes are used to form the p-type electrode 6). Use the physical vapor deposition magnetron sputtering process to deposit the n-type electrode 5 on the n-type gallium nitride layer 23 and deposit the p-type electrode 6 on the p-type gallium nitride layer 4. Finally, package the LED chip onto the circuit board 8 through SMD.

[0081] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A white light backlight source using a blue-green dual-peak single crystal chip, characterized in that, It includes a packaging structure and an LED chip disposed within the packaging structure; The LED chip includes a substrate, a blue-green dual-peak single-crystal chip, and a red light conversion layer stacked in sequence from bottom to top. The blue-green dual-peak single-crystal chip includes a short-wavelength blue gallium nitride layer that emits blue light electro-optically and a green light conversion layer that emits light photoluminescently. The red light conversion layer contains a red fluoride phosphor or a red composite fluoride phosphor.

2. The white light backlight source using a blue-green dual-peak single crystal chip according to claim 1, wherein The red light conversion layer is a thin film layer stacked on the blue-green dual-peak single-crystal chip, or the red light conversion layer is coated on the surface of the blue-green dual-peak single-crystal chip.

3. The white light backlight source using a blue-green dual-peak single crystal chip according to claim 1, characterized in that, It further includes an organic carrier surrounding the red light conversion layer. The red fluoride phosphor or the red composite fluoride phosphor is dispersed in the organic carrier. The organic carrier includes any one or a combination of optical silica gel and optical epoxy glue. The thickness of the red light conversion layer above the blue-green dual-peak chip is 25 - 500 microns.

4. The white light backlight source using a blue-green dual-peak single crystal chip according to claim 1, characterized in that, The blue and green light emitted by the blue-green dual-peak single-crystal chip is directed towards the red light conversion layer, so that the red light wavelength conversion material emits red light.

5. The white light backlight source using a blue-green dual-peak single crystal chip according to claim 1, wherein The packaging structure includes a lens and a circuit board, and the lens encapsulates the LED chip on the circuit board.

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