Mixed light source of ultraviolet and visible light and method for producing the same

Abstract

This invention provides a hybrid ultraviolet and visible light source and its fabrication method. The method includes the following steps: providing a substrate, the substrate including a first region and a second region, the second region surrounding the first region; using a first mask to block the second region, and forming a first ohmic layer and a first N-type layer in the first region; using third, fourth, and fifth masks to form first, second, and third monochromatic light-emitting quantum well layers on the surface of the first N-type layer, respectively; using a second mask to form a first P-type layer, forming a white light source stacked structure; using a sixth mask to block the first region and forming an ultraviolet light source stacked structure in the second region; and simultaneously forming electrodes in both the white light source region and the ultraviolet light source region. The white light source for illumination proposed in the above technical solution does not contain phosphors or light-emitting quantum dots, and can extend its lifespan and reduce energy consumption when used in conjunction with an ultraviolet light source.

Description

Technical Field

[0001] This invention relates to the field of ultraviolet light sources, and more particularly to a hybrid light source of ultraviolet and visible light and its preparation method. Background Technology

[0002] With the continuous development of semiconductor technology, ultraviolet LEDs (Light Emitting Diodes) have been widely used in air and water purification, disinfection, ultraviolet medicine, and high-density optical storage systems. Traditional light source structures used in refrigerators, lighting disinfection lamps, and other equipment generally include an illumination source and an ultraviolet source, with the illumination source typically being a white LED module. The first method uses phosphor colloids (fluorescent gels) to form white light; the second method uses LEDs to excite quantum dots to form white light; and the third method stacks multiple colored quantum wells together to form a white LED.

[0003] However, when using phosphor colloids (phosphor gels) to generate white light, the ultraviolet light emitted by the ultraviolet light source can accelerate the aging of the phosphor colloids (phosphor gels) in the lighting source. The light source chip of the lighting source is exposed to ultraviolet light all around, which will accelerate the aging of the phosphor colloids and affect the lifespan of the lighting LED module. The second method, using light-emitting quantum dots to achieve white LED lighting, also has certain drawbacks. For example, the diameters of light-emitting quantum dots of different colors are different. For example, the diameter of red light quantum dots is larger, roughly equivalent to the size of 50 atoms, while the diameter of green light quantum dots is smaller, roughly equivalent to the size of 30 atoms. The different diameters of quantum dots of different colors make it difficult to control the uniformity of light when the quantum dots are excited to produce different colors of light, which can easily lead to color differences. On the other hand, the power consumption of quantum dot light-emitting LEDs is relatively high. The energy consumption of light emission through quantum dot excitation will increase by more than 20%. The third method involves stacking quantum wells of different colors together, such as green, blue, and red quantum wells, to form a bottom-up stacked structure. This allows for the emission of white light through multiple colors. The drawback of this structure is that it increases the thickness of the LED, which is detrimental to current transmission and heat dissipation.

[0004] Therefore, there is a need for an ultraviolet light source device that combines lighting and disinfection functions, has a longer lifespan, better luminous effect, and smaller size. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to make the ultraviolet light source have a longer lifespan, better light emission effect and smaller size, and to provide a hybrid light source of ultraviolet and visible light and its preparation method.

[0006] To address the aforementioned problems, the present invention provides a hybrid light source combining ultraviolet and visible light, characterized in that it comprises: a substrate; a first region and a second region on the surface of the substrate, wherein the second region surrounds the first region; at least one white light source located in the first region, formed by mixing multiple monochromatic LEDs; and an ultraviolet light source located in the second region.

[0007] To address the aforementioned problems, this invention provides a method for fabricating a hybrid ultraviolet and visible light source, characterized by the following steps: providing a substrate comprising a first region and a second region, wherein the second region surrounds the first region; using a first mask to shield the second region and forming a first ohmic layer and a first N-type layer in the first region; using a third, fourth, and fifth mask to form a first monochromatic light-emitting quantum well layer, a second monochromatic light-emitting quantum well layer, and a third monochromatic light-emitting quantum well layer on the surface of the first N-type layer, respectively; using a second mask to form a first P-type layer, forming a white light source stacked structure; using a sixth mask to shield the first region and forming an ultraviolet light source stacked structure in the second region; and simultaneously forming electrodes in the white light source region and the ultraviolet light source region.

[0008] The white light source proposed in the above technical solution for illumination does not contain fluorescent adhesive or luminescent quantum dots, and can extend its lifespan and reduce energy consumption when used in conjunction with an ultraviolet light source. The ultraviolet light source surrounding the white light source increases the usable area of ​​the substrate, and the ultraviolet and white light sources are controlled independently, allowing each to emit light independently, thus expanding its application range. Attached Figure Description

[0009] Appendix Figure 1A The diagram shown is a structural schematic of a specific embodiment of the hybrid ultraviolet and visible light source described in this invention.

[0010] Appendix Figure 1B The attached image shows... Figure 1A A magnified view of a portion of region 109.

[0011] Appendix Figure 2 The diagram shows a flowchart of a specific embodiment of the method for preparing a hybrid ultraviolet and visible light source according to the present invention.

[0012] Appendix Figure 3A ~Attached Figure 3F The diagram shown is a process flow chart illustrating a specific embodiment of the method for preparing the hybrid ultraviolet and visible light source described in this invention. (See attached diagram.) Figure 1B The formation steps corresponding to the cross-sectional view along the AA' direction.

[0013] Appendix Figure 4A ~Attached Figure 4FThe diagram shown is a process flow chart illustrating a specific embodiment of the method for preparing the hybrid ultraviolet and visible light source described in this invention. (See attached diagram.) Figure 1B The formation steps corresponding to the cross-sectional view along the BB' direction. Detailed Implementation

[0014] The following detailed description, in conjunction with the accompanying drawings, illustrates the specific implementation of the hybrid ultraviolet and visible light source and its preparation method provided by the present invention.

[0015] Appendix Figure 1A The diagram shows a schematic representation of a specific embodiment of the hybrid ultraviolet and visible light source of the present invention. The hybrid ultraviolet and visible light source includes a substrate 10, a white light source 11, an ultraviolet light source 12, and multiple pads. The visible light is white light. The substrate 10 includes a first region and a second region, wherein the second region surrounds the first region. The substrate 10 is typically constructed using a silicon carbide substrate, a silicon substrate, or a sapphire substrate, with a buffer layer formed on the substrate 10. Since the present invention only uses the white light source 11 and ultraviolet light source 12 for illumination, a gallium nitride substrate is not required for the substrate 10. Although gallium nitride substrates can form LED structures with low dislocation density, the LED chips of the present invention are relatively large, unlike the micro LED structures used for displays, requiring higher crystal quality. Based on meeting the requirements for illumination and sterilization, a lower-cost silicon substrate or sapphire substrate can be used for the substrate 10 of the present invention.

[0016] The first region includes at least one of the white light sources 11, and the white light source 11 is formed by mixing multiple monochromatic LEDs. In one specific embodiment, there are multiple white light sources 11 arranged in an array.

[0017] The second region includes an array of ultraviolet light sources 12 surrounding the white light source 11. In this structure, the white light source 11 is located in the center, and the ultraviolet light sources 12 are on the outer periphery.

[0018] The substrate 10 further includes a third region, wherein pads are disposed in the third region. The pads include a first pad 101, a second pad 102, a third pad 103, and a fourth pad 104. The first pad 101 and the second pad 102 are electrically connected to the white light source 11 (shown in the attached diagram). Figure 1B The third pad 103 and the fourth pad 104 are electrically connected to the ultraviolet light source 12 (shown in the attached diagram). Figure 1B This allows for individual control of the white light source 11 and the ultraviolet light source 12, ensuring that the white light source 11 and the ultraviolet light source 12 can be turned on separately when the ultraviolet light source 12 is needed or when lighting is required.

[0019] The second region of the ultraviolet light source 12 and the pad region surround the first region (the region where the white light source 11 is located) inside, which can make full use of the substrate 10 region to form a compact mixed light source of ultraviolet and visible light with both lighting and sterilization functions.

[0020] Appendix Figure 1B The image shown is a partial enlarged view of region 109 of a specific embodiment of the hybrid ultraviolet and visible light source described in this invention. In one specific embodiment, the white light source 11 includes three monochromatic LEDs arranged in a triangular pattern. Specifically, the white light source 11 has only one monochromatic LED on the side closer to the first pad 101 or the second pad 102, and two other monochromatic LEDs on the side farther from the first pad 101 or the second pad 102. The three monochromatic LEDs are red, green, and blue, respectively. The three monochromatic LEDs share an N-type layer and an ohmic contact layer, enabling simultaneous switching of the three monochromatic LEDs. A first electrode 111 of the white light source 11 is formed near the first pad 101 and connected to the second pad 102. Second electrodes 112 of the white light source 11 are formed on the surfaces of the three monochromatic LEDs, and the second electrodes 112 on the surfaces of the three monochromatic LEDs are connected by wires and electrically connected to the first electrode 111 of the preceding white light source 11, thus forming a series structure of multiple white light sources 11. At the other end of the series structure, the second electrode 112 of the white light source 11 is connected to the first pad 101 (not shown). Near the fourth pad 104, the first electrode 121 of the ultraviolet light source 12 is also formed and electrically connected to the fourth pad 104. The second electrode 122 of the ultraviolet light source 12 is electrically connected to the third pad 103 (not shown).

[0021] Appendix Figure 2 The diagram shows a flowchart of a specific embodiment of the method for preparing a hybrid ultraviolet and visible light source according to the present invention, including the following steps: Step S21, providing a substrate, the substrate including a first region and a second region, wherein the second region surrounds the first region; Step S22, using a first mask to block the second region, and forming a first ohmic layer and a first N-type layer in the first region; Step S23, using a third mask, a fourth mask, and a fifth mask respectively to form a first monochromatic light-emitting quantum well layer, a second monochromatic light-emitting quantum well layer, and a third monochromatic light-emitting quantum well layer on the surface of the first N-type layer; Step S24, using a second mask to form a first P-type layer, forming a white light source stacked structure; Step S25, using a sixth mask to block the first region and forming an ultraviolet light source stacked structure in the second region; Step S26, simultaneously forming electrodes in the white light source region and the ultraviolet light source region.

[0022] Since the substrate has multiple repeating regions, these repeating regions can be formed simultaneously during fabrication using a specific mask structure. The following explanation uses one of these regions as an example. (Appendix) Figure 3A ~Attached Figure 3F and appendix Figure 4A ~Attached Figure 4F The diagram shown is a process flow chart illustrating a specific embodiment of the method for preparing the hybrid ultraviolet and visible light source described in this invention. Figure 3A ~Attached Figure 3F Selected accessories Figure 1B The formation steps corresponding to the cross-sectional view along the AA' direction are attached. Figure 4A ~Attached Figure 4F Selected accessories Figure 1B The formation steps corresponding to the cross-sectional view along the BB' direction.

[0023] Appendix Figure 3A and appendix Figure 4A As shown, and referring to step S21, a substrate 30 is provided. The substrate 30 includes a first region and a second region, wherein the second region surrounds the first region. The substrate 30 also includes a third region, wherein pads are disposed in the third region. The pads include a first to a fourth pad, the first pad and the second pad being electrically connected to a white light source, and the third pad and the fourth pad being electrically connected to an ultraviolet light source.

[0024] The substrate 30 structure is typically based on a silicon carbide substrate, a silicon substrate, or a sapphire substrate, with a buffer layer 301 formed on the substrate 30. Since this invention is only for white light and ultraviolet light sources, a gallium nitride substrate is not required for the substrate 30. Although gallium nitride substrates can form LED structures with low dislocation densities, the LED chips in this invention are relatively large, unlike micro LED structures used for displays, requiring higher crystal quality. To meet the requirements of lighting and sterilization, the substrate 30 of this invention uses a lower-cost silicon or sapphire substrate, thus reducing production costs.

[0025] To improve the crystal quality of the upper LED's light-emitting layer, a buffer layer 301 is first formed on the entire substrate 30 before forming the N-type layer. In one specific embodiment, the buffer layer 301 is made of GaN. During the formation of the buffer layer 301, the temperature within the chamber is maintained at a first temperature, and the pressure within the chamber is maintained at a first pressure. The first temperature range is 900°C-1050°C, and the first pressure is 120 mbar-150 mbar. When the buffer layer 301 is formed at a lower temperature, gallium nitride (GaN) nucleates along the nucleation region, forming multiple island-shaped GaN structures. At lower temperatures, when multiple small and densely packed GaN grains form a GaN layer, there are certain gaps between the island grains. Although at high temperatures the grains deform to close the gaps in order to reduce surface energy, at low temperatures there are still certain gaps between the small island grains, forming a loose structure. This loose structure can alleviate stress.

[0026] Appendix Figure 3B and appendix Figure 4B As shown, and referring to step S22, the second region is masked using a first mask 391, and a first ohmic contact layer 311 and a first N-type layer 312 are formed in the first region.

[0027] After forming a buffer layer 301 on the entire substrate 30, a first mask 391 is used to shield the second and third regions, exposing the first region, where a first ohmic contact layer 311 is formed. In one specific embodiment, the first ohmic contact layer 311 is a superlattice structure, which allows a two-dimensional gas of electrons with high mobility to form within its layers, thereby increasing carrier mobility and reducing contact resistance. The superlattice structure comprises multiple periods; in a particular example, each period includes an N-type gallium nitride (N-GaN) sublayer with a thickness of 80 nm to 100 nm and an undoped aluminum gallium nitride (AlGaN) sublayer with a thickness of 10 nm to 25 nm, such as 5 GaN sublayers and 4 AlGaN sublayers, with the N-GaN layer doped to a concentration of 1 × 10⁻⁶. 18 atoms / cm 3 The first ohmic contact layer 311, which forms the superlattice, is deposited in an MOCVD device at a temperature of 1100℃ to 1180℃ and a chamber pressure of 180mbar to 200mbar. The temperature and pressure of forming the first ohmic contact layer 311 are both higher than those of forming the buffer layer 301, which facilitates the formation of a high-crystallinity ohmic contact layer.

[0028] A first N-type layer 312, with a wavelength of 800 nm to 1000 nm, is formed on the surface of the first ohmic contact layer 311. The first N-type layer 312 is an N-type gallium nitride layer, and its N-type doping source is SiH4 with a doping concentration of 5 × 10⁻⁶. 17atoms / cm 3 ~8×10 17 atoms / cm 3 The first N-type layer 312 is formed in the same chamber, with the temperature and pressure inside the chamber remaining constant. An N-type doping source is introduced to form the first N-type layer 312 with a specific doping concentration.

[0029] Appendix Figure 3C and appendix Figure 4C As shown, and referring to step S23, a first monochromatic light-emitting quantum well layer, a second monochromatic light-emitting quantum well layer, and a third monochromatic light-emitting quantum well layer are formed on the surface of the first N-type layer 312 using the third mask, the fourth mask, and the fifth mask, respectively.

[0030] In one specific embodiment, before forming the first monochromatic light-emitting quantum well layer, the second monochromatic light-emitting quantum well layer, and the third monochromatic light-emitting quantum well layer on the surface of the first N-type layer 312 using the third, fourth, and fifth photomasks, the following steps are further included: spin-coating a photoresist layer 313 onto the first N-type layer 312, and processing the photoresist layer 313 using the second photomask to form a first opening region, a second opening region, and a third opening region on the photoresist layer 313, wherein the opening regions expose the first N-type layer 312. The photoresist can be a positive photoresist material or a negative photoresist material. In one specific embodiment, the photoresist is a positive photoresist layer. Then, the photoresist layer 313 is baked and cured to form a photoresist layer 313 on the surface of the first N-type layer 312.

[0031] The photoresist layer 313 is processed using a second mask to form a first opening region, a second opening region, and a third opening region, which expose the first N-type layer 312. In one specific embodiment, the second mask has multiple openings, with three openings corresponding to the locations of three monochrome LEDs. Each opening position corresponds to the location of the light-emitting area forming the monochrome LED. The photoresist layer 313 is exposed and developed using the second mask, forming openings on the photoresist layer 313 and exposing the underlying first N-type layer 312.

[0032] A first light-emitting quantum well layer 314, a second light-emitting quantum well layer 315, and a third light-emitting quantum well layer 316 are formed in the first opening region, the second opening region, and the third opening region, respectively. An epitaxial structure of an N-type gallium nitride layer 312 with multiple exposed openings is placed in a deposition apparatus. A first mask 391 is used to block the second and third regions, and a third mask is used to block the second and third opening regions, respectively. The first light-emitting quantum well layer 314 is deposited on the surface of the N-type gallium nitride layer 312 in the first opening region. Before forming the first light-emitting quantum well layer 314, the exposed surface of the N-type gallium nitride layer 312 is treated with hydrogen to remove residual photoresist, water, oxygen, and other impurities, ensuring the formation of a high-quality quantum well layer. In one specific embodiment, the first opening region is a blue LED region, and the first light-emitting quantum well layer 314 is a blue light-emitting quantum well layer. In this embodiment, the blue light-emitting quantum well layer uses In... x Ga 1-x N / GaN blue light multiple quantum wells, growing 5 to 20 pairs of blue light In x Ga 1-x N / GaN quantum well light-emitting region, where In x Ga 1- x The thickness of the N quantum well layer is 2nm to 6nm, the thickness of the GaN quantum barrier layer is 10nm to 20nm, and the range of x is 0.15 to 0.20.

[0033] The third mask is removed, and a fourth mask is used to block the first and third opening regions, respectively. A second light-emitting quantum well layer 315 is formed on the N-type gallium nitride 312 surface exposed in the second opening region. In one specific embodiment, the second opening region is a green LED region, and the second light-emitting quantum well layer 315 is a green light-emitting quantum well layer. In this embodiment, the green light-emitting quantum well layer grows 5 to 20 pairs of green In LEDs. y Ga 1-y N / GaN quantum well light-emitting region, where In y Ga 1-y The thickness of the N quantum well layer is 2nm to 6nm, the thickness of the GaN quantum barrier layer is 10nm to 20nm, and the range of y is 0.20 to 0.40.

[0034] The fourth mask is removed, and a fifth mask is used to block the first and second opening regions, respectively. A third light-emitting quantum well layer 316 is formed on the N-type gallium nitride 312 surface exposed in the third opening region. In one specific embodiment, the third opening region is a red LED region, and the third light-emitting quantum well layer 316 is a red light-emitting quantum well layer. In this embodiment, the red light-emitting quantum well layer emits red (Al) light. z Ga 1-z) a In 1-a P / (Al b Ga 1-b ) c In 1-c The p-multiple quantum well emitting region has 5 to 20 pairs of red-light multiple quantum wells, with a well layer thickness of 3 to 5 nm and a barrier layer thickness of 10 to 20 nm. The well layer (Al) z Ga 1-z ) a In 1-a P has z = 0.1, a = 0.9, and the barrier layer (Al) b Ga 1-b ) c In 1-c P has a b of 0.5 and a c of 0.5. After forming light-emitting quantum well layers in all three monochrome LED regions, the fifth mask is removed.

[0035] Appendix Figure 3D and appendix Figure 4D As shown, and referring to step S24, a first P-type layer 317 is formed using a second mask to form a white light source stack structure. In one specific embodiment, the first P-type layer 317 is simultaneously formed on the surface of the light-emitting quantum well layer in the three monochromatic LED regions using the second mask. The first P-type layer 317 is a P-type gallium nitride layer with a doping concentration of 5 × 10⁻⁶. 18 atoms / cm 3 ~8×10 18 atoms / cm 3 The thickness of the first P-type layer 317 is 50nm to 150nm. After forming the first P-type layer 317, the excess photoresist layer 313 and the first mask 391 are removed.

[0036] After completing the above steps, you will obtain the attached document. Figure 3D and appendix Figure 4DThe diagram shows a white light source formed by mixing multiple monochromatic LEDs in the first region. Multiple white light sources are arranged in an array in the first region; each white light source includes three monochromatic LEDs arranged in a triangular pattern, with only one monochromatic LED near the first or second pad. The quantum well layers of the three monochromatic LEDs are formed in the same chamber; the three monochromatic LED structures share an N-type layer and an ohmic contact layer. In this invention, the length and width of each monochromatic LED are between 150 and 300 micrometers, and the spacing between the monochromatic LEDs is between 30 and 100 micrometers. For achieving white light illumination, the relatively large size and spacing of the monochromatic LEDs allow for better control of chip yield and reduced manufacturing costs. Each white light source has three monochromatic LEDs connected through the same ohmic contact layer, enabling synchronous emission. The three monochromatic LED chips are red, green, and blue, and the three-color LEDs can form a soft white light source. This white light source does not use phosphors or quantum dot luminescent materials and, when used in conjunction with an ultraviolet light source, can improve lifespan and reduce energy consumption.

[0037] Continue to refer to the appendix Figure 3E and appendix Figure 4E As shown, in step S25, a sixth mask 392 is used to shield the first region and form an ultraviolet light source stack structure in the second region. The sixth mask 392 is used to shield both the first and third regions, exposing the second region, and a second ohmic contact layer 321 is formed on the buffer layer 301 of the second region. In one specific embodiment, the second ohmic contact layer 321 is an ohmic contact layer of a GaN / AlN / GaN superlattice. The superlattice structure includes multiple periods; in a particular example, each period includes a GaN sublayer with a thickness of 10 nm to 20 nm and an AlN sublayer with a thickness of 10 nm to 25 nm. The AlN and GaN sublayers can be doped with Mg to improve the ohmic contact performance; 10 to 20 periods of GaN and AlN can be used, and the total thickness of the second ohmic contact layer 321 is 300 nm to 600 nm. The second ohmic contact layer 321 is deposited in an MOCVD equipment at a temperature of 1000℃~1100℃ and a chamber pressure of 180mbar~200mbar to form a high-crystallinity ohmic contact layer.

[0038] Then, in the same chamber, a Ga source, an Al source, a nitrogen source, and an N-type doped source are simultaneously introduced at a temperature of 1050℃ to 1150℃ to grow a second N-type layer on the surface of the second ohmic contact layer 321. The second N-type layer further comprises an N-type AlGaN layer 322 and an Al-gradiented N-type Al... a Ga 1-a N layers 323, and Al-gradient N-type Al a Ga1-a The doping concentration of the N-layer 323 is greater than that of the N-type AlGaN layer 322. The N-type dopant source for the N-type AlGaN layer 322 is SiH4, with a doping concentration of 5 × 10⁻⁶. 17 atoms / cm 3 ~8×10 17 atoms / cm 3 The thickness of the N-type AlGaN layer 322 grown is 600 nm to 850 nm.

[0039] An Al-gradientd N-type Al was grown on the surface of an N-type AlGaN layer 322. a Ga 1-a N-layer 323. Al-gradient N-type Al a Ga 1-a The N-layer 323 can suppress the quantum-confined Stark effect, thereby weakening the polarization electric field of the upper active layer and improving the quantum efficiency within the deep ultraviolet LED, thus enhancing its luminous efficiency. (Al-graded N-type Al) a Ga 1-a N-layer 323 can include 15 to 20 layers of Al. a Ga 1-a The N-layer, with the bottommost layer and the topmost AlGaN layer having the general chemical formula Al a Ga 1-a N, where a ranges from 0.2 to 0.65. The value of a gradually increases from bottom to top, with Al at the top. 0.65 Ga 0.35 N. The gradual change in Al content can be controlled by adjusting the amount of Al source introduced, where each Al layer... a Ga 1-a The thickness of N is 5nm to 10nm, and the thickness of the Al graded layer is between 80nm and 150nm. (Al graded N-type Al) a Ga 1-a The N-type dopant concentration in the N-layer 323 is 9 × 10⁻⁶. 17 atoms / cm 3 ~15×10 17 atoms / cm 3 The dopant concentration of the N-type Al graded layer is greater than that of the N-type AlGaN layer 322, which improves both the internal quantum efficiency and the carrier concentration.

[0040] In Al-gradient N-type Al a Ga 1-a An active region layer 324 is formed on the surface of the N-layer 323. The active region layer 324 has an alternating structure of quantum wells and quantum barriers, and is also made of AlGaN material, formed within the same chamber. The active layer is formed of Al... 0.5 Ga0.5 N / Al 0.15 Ga 0.85 The active region layer 324 has an alternating structure of N quantum wells and quantum barriers. The period of the quantum wells and quantum barriers in the active region layer 324 is 5 to 10 periods, and each period structure includes Al... 0.5 Ga 0.5 N quantum barrier layer, and Al 0.15 Ga 0.85 N quantum well layers, where Al 0.5 Ga 0.5 The thickness of the N quantum barrier layer can be 8nm to 15nm, Al 0.15 Ga 0.85 The thickness of the N-quantum well layer can be 4 nm to 10 nm.

[0041] Then, the aluminum source is stopped, and a second P-type layer 325 is formed on the surface of the active region layer 324. The P-type dopant source is magnesia-diocene, and the doping concentration of the P-type dopant source is 5 x 10⁻⁶. 18 atoms / cm 3 ~15x10 18 atoms / cm 3 The thickness of the second P-type layer 325 formed is 50nm to 150nm.

[0042] After completing the above steps, the ultraviolet light source stack structure located in the second region is obtained.

[0043] In addition, see attached document Figure 3F and appendix Figure 4F As shown, and referring to step S26, electrodes are simultaneously formed in both the white light source and the ultraviolet light source regions. Etching is performed on the first electrode 111 region in the white light source region and the first electrode 121 region in the ultraviolet light source region to form an opening / groove in the first electrode 111 region, exposing the first ohmic contact layer 311 and the second ohmic layer 321. A transparent conductive layer is sputtered or deposited on the surface of the first electrode 111 region to form the first electrode 111 of the white light source and the first electrode 121 of the ultraviolet light source. Etching can be performed using a combination of photolithography and dry etching. The transparent conductive layer can be ITO or IZO. Then, a transparent conductive layer is sputtered or deposited on the surface of the first P-type layer 317 in the white light source region and the second P-type layer 325 in the ultraviolet light source region to form the second electrode 112 of the white light source and the second electrode 122 of the ultraviolet light source. The transparent conductive layer can be ITO or IZO.

[0044] After forming the electrodes, the second electrodes 112 of the monochromatic LEDs in the multiple white light sources are electrically connected using wires and are also electrically connected to the first electrodes 111 of adjacent white light sources. In this way, the positive electrode of one of the multiple white light sources is connected to the negative electrode of another, forming multiple series-connected white light sources. In each white light source, three trichromatic LEDs are arranged in an inverted pyramid shape, and there is one monochromatic LED chip on the side close to the pad, which facilitates leading out wires for electrical connection to the pad. The three monochromatic LED chips share the N-type layer and the ohmic contact layer, so that the simultaneous switching of the three chips can be controlled synchronously to achieve the simultaneous emission of three colors of light and the mixing of light to form white light. After the second electrodes 112 of the three monochromatic LEDs are connected together, they are electrically connected to the first electrode 121 of another adjacent white light source, so that multiple white light sources can be connected in series to achieve the lighting effect.

[0045] On the surface of the third region of the substrate 30, first pads and second pads for connecting the white light sources, and third pads and fourth pads for connecting the ultraviolet light sources are formed. The white light sources and the ultraviolet light sources are controlled by separate circuits, and both can be powered on and emit light separately, expanding the scope of use.

[0046] In the present invention, each white light LED module has three monochromatic LED chips. The three monochromatic LED chips are connected through the same ohmic contact layer, enabling synchronous light emission. The three monochromatic LED chips are red, green, and blue. The three-color LED chips can form a soft white light LED lighting module. This LED lighting module does not use fluorescent glue and quantum dot light-emitting materials. When used in conjunction with deep ultraviolet LEDs, it can extend the service life and reduce energy consumption. In each white light LED module, the three three-color LED chips are arranged in an inverted "pin" shape, and there is one monochromatic LED chip on the side close to the pad, which facilitates leading out wires for electrical connection to the pad. The three monochromatic LED chips share the N-type layer and the ohmic contact layer, so that the simultaneous switching of the three chips can be controlled synchronously to achieve the simultaneous emission of three colors of light and the mixing of the three colors of light to form white light. After the upper electrodes (second electrodes) of the three monochromatic LED chips are connected together, they are electrically connected to the lower electrodes (first electrodes) of another adjacent white light LED module, so that multiple white light LED modules can be connected in series to achieve the lighting effect.

[0047] At the same time, the white light source proposed in the present invention for lighting does not have fluorescent glue and light-emitting quantum dots, and can extend the service life and reduce energy consumption when used in conjunction with ultraviolet light sources. The ultraviolet light sources surround the white light sources, which can increase the utilization area of the substrate. Moreover, the ultraviolet light sources and the white light sources are controlled separately, and both can be powered on and emit light separately, expanding the scope of use.

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A hybrid light source combining ultraviolet and visible light, characterized in that, include: Substrate; The substrate surface has a first region and a second region, wherein the second region surrounds the first region; At least one white light source located in the first region, formed by mixing multiple monochromatic LEDs; The ultraviolet light source is located in the second region; The white light source includes a first N-type layer and a first ohmic contact layer stacked together, wherein multiple monochromatic LEDs in the white light source share the first N-type layer and the first ohmic contact layer; the ultraviolet light source includes a second N-type layer, which includes an N-type AlGaN layer and an Al-gradient N-type Al layer disposed on the N-type AlGaN layer. a Ga 1-a N layers, and an N-type Al with a gradient of Al. a Ga 1-a The doping concentration of N is greater than that of the N-type AlGaN layer, and the range of a is 0.2–0.65, with Al gradually increasing for the N-type Al. a Ga 1-a The value of 'a' in each of the N layers gradually increases from bottom to top.

2. The hybrid ultraviolet and visible light source according to claim 1, characterized in that, It also includes a third region, which is provided with pads, including first to fourth pads. The first and second pads are electrically connected to the white light source, and the third and fourth pads are electrically connected to the ultraviolet light source.

3. The hybrid ultraviolet and visible light source according to claim 2, characterized in that, The first region has multiple white light sources arranged in an array; each white light source includes three monochrome LEDs arranged in a triangular pattern, wherein the side of the white light source closest to the first pad or the second pad has only one monochrome LED; the three monochrome LEDs are blue, green and red, respectively.

4. The hybrid ultraviolet and visible light source according to claim 3, characterized in that, The white light source also includes: The first electrode is located near the first pad or the second pad; The second electrode is formed on the surface of the three monochromatic LEDs; The second electrodes on the surfaces of the three monochrome LEDs are electrically connected to each other and electrically connected to the first electrode of the previous white light source, and the multiple white light sources form a series structure.

5. A method for preparing a hybrid light source of ultraviolet and visible light, characterized in that, Includes the following steps: A substrate is provided, the substrate including a first region and a second region, wherein the second region surrounds the first region; The second region is masked using a first mask, and a first ohmic layer and a first N-type layer are formed in the first region; A first monochromatic light-emitting quantum well layer, a second monochromatic light-emitting quantum well layer, and a third monochromatic light-emitting quantum well layer are formed on the surface of the first N-type layer using a third mask, a fourth mask, and a fifth mask, respectively. The first monochromatic light-emitting quantum well layer, the second monochromatic light-emitting quantum well layer, and the third monochromatic light-emitting quantum well layer share the first ohmic layer and the first N-type layer. A first P-type layer is formed using a second mask to create a stacked structure of a white light source. The first region is blocked using a sixth mask, and an ultraviolet light source stacking structure is formed in the second region; The ultraviolet light source includes a second N-type layer, which comprises an N-type AlGaN layer and an Al-gradient N-type Al layer disposed on the N-type AlGaN layer. a Ga 1-a N layers, and an N-type Al with a gradient of Al. a Ga 1-a The doping concentration of N is greater than that of the N-type AlGaN layer, and the range of a is 0.2–0.65, with Al gradually increasing for the N-type Al. a Ga 1-a The value of 'a' in each of the N layers gradually increases from bottom to top; Electrodes are formed simultaneously in both the white light source region and the ultraviolet light source region.

6. The method according to claim 5, characterized in that, It also includes a third region, which is provided with pads, including first to fourth pads. The first and second pads are electrically connected to the white light source, and the third and fourth pads are electrically connected to the ultraviolet light source.

7. The method according to claim 6, characterized in that, The first region has multiple white light sources arranged in an array; each white light source includes three monochromatic LEDs arranged in a triangular pattern, wherein the side of the white light source closest to the first pad or the second pad has only one monochromatic LED; the light-emitting quantum well layers of the three monochromatic LEDs are formed in the same chamber.

8. The method according to claim 7, characterized in that, A first electrode is formed near the pad of the white light source, and a second electrode is formed on the surface of the three monochrome LEDs; the second electrodes of the three monochrome LEDs are electrically connected to each other and electrically connected to the first electrode of the previous white light source, and the multiple white light sources form a series structure.

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