A photoelectric chip structure with high internal quantum efficiency and its design method
By inserting replacement layers into the quantum barrier layer and electron barrier layer of the AlGaN deep ultraviolet photoelectric chip, the energy band structure is optimized, and the problem of low quantum efficiency in deep ultraviolet LEDs is solved, and the optoelectronic chip structure with high internal quantum efficiency and high luminous efficiency is achieved.
Patent Information
- Application Number
- CN202411419073.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-12
- Publication Date
- 2025-08-22
- Estimated Expiration
- 2044-10-12
AI Technical Summary
The deep ultraviolet LED laser technology is immature and has low internal quantum efficiency. Especially the AlGaN deep ultraviolet photoelectric chip structure with a wavelength of less than 300nm is generally less than 10%, which is difficult to meet market demand.
The replacement layers are inserted into the quantum barrier layer and the electron barrier layer respectively to optimize the quantum barrier energy belt barrier height and hole effective barrier height, and improve the internal quantum efficiency and luminous efficiency by improving the optoelectronic chip structure.
It significantly improves the internal quantum efficiency and luminous efficiency of AlGaN deep ultraviolet photoelectric chips, meets market-oriented demands, and improves production efficiency.
Smart Images

Figure CN119381892B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of communication technology, and in particular to a photoelectric chip structure with high internal quantum efficiency and a design method thereof. Background Art
[0002] With the development of III-V nitride material growth technology and breakthroughs in related device processes in recent years, the performance of AlGaN-based ultraviolet light-emitting chip structures has been significantly improved and has been widely used in many fields such as medical care, communications, display, and biochemical testing.
[0003] The ultraviolet photoelectric chip structure is a semiconductor photoelectric device with a light-emitting wavelength between 200 and 400nm. Compared with traditional ultraviolet light sources, such as mercury lamps, deep ultraviolet LEDs have the advantages of small size, low power consumption, long life, and continuously adjustable light-emitting wavelength. They have broad application prospects in the fields of medical treatment, purification, laser, etc. and have huge development potential. However, at present, deep ultraviolet LED laser technology is not mature, and the internal quantum efficiency is much lower than that of mature nitride blue light LED chip structures. In particular, the AlGaN deep ultraviolet photoelectric chip structure with a wavelength less than 300nm is generally less than 10%, which is difficult to meet market demand. Summary of the Invention
[0004] The technical problem to be solved by the present invention is that deep ultraviolet LED laser technology is not mature, and its internal quantum efficiency is much lower than that of mature nitride blue light LED chip structures; especially in ultraviolet lasers, the wavelength of aluminum gallium nitride (AlGaN) material is usually designed to be in the range of 200 to 365 nanometers, while the AlGaN deep ultraviolet optoelectronic chip structure with a wavelength less than 300nm is generally less than 10%, which is difficult to meet market demand. This solution provides a high internal quantum efficiency optoelectronic chip structure and its design method. For AlGaN deep ultraviolet optoelectronic chip structures with wavelengths less than 300nm, based on the traditional aluminum gallium nitride (AlGaN) optoelectronic chip structure, structural and design method improvements are made. By replacing the first replacement layer in some or all of the quantum barrier layers while maintaining a constant thickness of the quantum barrier layer, and replacing the second replacement layer in the electron blocking layer while maintaining a constant thickness of the electron blocking layer, the improved optoelectronic chip structure increases the quantum barrier band barrier height and reduces the effective hole barrier height, greatly improving the radiative recombination efficiency of the active region, thereby effectively improving the internal quantum efficiency and luminous efficiency of the AlGaN deep ultraviolet optoelectronic chip structure. In addition, this solution also provides a specific design method for optoelectronic chip structures with high internal quantum efficiency. Through a parameter combination model, dynamic parameters are adjusted according to unit adjustment amounts to combine multiple dynamic parameter groups. Only the dynamic parameter group groups are simulated and calculated to determine the optimal dynamic parameter group. This avoids the simulation and calculation of a large number of parameters, thereby improving the production efficiency of optoelectronic chip structures with high internal quantum efficiency.
[0005] This solution provides a photoelectric chip structure with high internal quantum efficiency, comprising: a buffer layer, an N-type layer, a multi-quantum well active layer, an electron blocking layer and a P-type layer stacked in sequence on a substrate layer;
[0006] The multi-quantum well active layer is formed by alternating and stacking n quantum barrier layers of the same material and thickness and n-1 quantum well layers of the same material and thickness;
[0007] When the thickness of the quantum barrier layer remains constant, a first replacement layer is inserted into part or all of the quantum barrier layer;
[0008] While the thickness of the electron blocking layer remains constant, a second replacement layer is inserted into the electron blocking layer.
[0009] Working Principle of This Solution: Deep ultraviolet LED laser technology is not mature, and its internal quantum efficiency is much lower than that of mature nitride blue light LED chip structures. In particular, AlGaN deep ultraviolet optoelectronic chip structures with wavelengths less than 300nm generally have an internal quantum efficiency of less than 10%, which is difficult to meet market demand. This solution provides an optoelectronic chip structure with high internal quantum efficiency and its design method. For AlGaN deep ultraviolet optoelectronic chip structures with wavelengths less than 300nm, based on the traditional aluminum gallium nitride (AlGaN) optoelectronic chip structure, structural and design method improvements are made. By replacing the first replacement layer in part or all of the quantum barrier layer while keeping the thickness of the quantum barrier layer constant; and replacing the second replacement layer in the electron blocking layer while keeping the thickness of the electron blocking layer constant, the improved optoelectronic chip structure increases the quantum barrier band barrier height and reduces the effective hole barrier height, greatly improving the radiative recombination efficiency of the active region, thereby effectively improving the internal quantum efficiency and luminous efficiency of the AlGaN deep ultraviolet optoelectronic chip structure.
[0010] A further optimization solution is that the position where the second replacement layer is replaced and inserted into the electron blocking layer includes: the second replacement layer is completely replaced and inserted above the electron blocking layer, the second replacement layer is completely replaced and inserted below the electron blocking layer, or the second replacement layer is symmetrically replaced and inserted above and below the electron blocking layer respectively.
[0011] A further optimization solution is that the first replacement layer is inserted into the middle position of the quantum barrier layer, and the center of the first replacement layer overlaps with the center of the quantum barrier layer.
[0012] As a preferred solution, the centers of the first quantum barrier layer, the third quantum barrier layer and the fifth quantum barrier layer are all replaced by the first replacement layer.
[0013] A further optimized solution is that the substrate layer is a sapphire layer with a thickness of 400 μm; the buffer layer is an AlN buffer layer with a thickness of 2000 nm;
[0014] The N-type layer is an n-Al layer with a thickness of 200 nm. 0.35 Ga 0.65 N layer; the doping concentration of n-type dopant is 5×10 18 cm -3 ;
[0015] The multi-quantum well active layer includes 6 quantum barrier layers and 5 quantum well layers; the quantum barrier layer is Al with a thickness of 15nm. 0.65 Ga 0.35 N layer; the quantum well layer is Al with a thickness of 2nm 0.35 Ga 0.65 N-layer;
[0016] The P-type layer is p-Al0 with a thickness of 200nm. 45 Ga 0.55 N layer; the doping concentration of p-type dopant is 5×10 19 cm -3 .
[0017] A further optimized solution is that the electron blocking layer is an Al2O3 layer with a thickness of 100 nm. x Ga 1-x N layer; x is the mole fraction of A1 in the electron blocking layer; 0.2 <x<0.8;
[0018] The second replacement layer includes a primary replacement layer and a secondary replacement layer; the primary replacement layer is Al x1 Ga (1-x1) N layer; the secondary replacement layer is Al x2 Ga (1-x2) N layers; x1 is the mole fraction of A1 in the primary substitution layer; x2 is the mole fraction of A1 in the secondary substitution layer; x>x1>x2;
[0019] Two identical primary replacement layers are respectively inserted above and below the electron blocking layer; and two identical secondary replacement layers are respectively inserted at the surface positions of the two primary replacement layers.
[0020] A further optimized solution is that the electron blocking layer is an Al2O3 layer with a thickness of 100 nm. 0.65 Ga 0.35 N layer; the first replacement layer is Al with a thickness of 5nm 0.68 Ga 0.32 N layer; the primary replacement layer is 15nm thick Al 0.6 Ga0.4N layer, the secondary replacement layer is 15nm thick Al 0.sc Ga 0.45 N layers.
[0021] This solution also provides a method for designing an optoelectronic chip structure, which is used to determine the optoelectronic chip structure with high internal quantum efficiency, including the following method:
[0022] Setting structural parameters and structural conditions of the optoelectronic chip structure, wherein the structural parameters include fixed parameters, dynamic parameters and unit adjustment amounts;
[0023] Inputting the structural parameters of the optoelectronic chip structure into the parameter combination model, and adjusting the dynamic parameters according to the unit adjustment amount to combine multiple dynamic parameter group sets;
[0024] The dynamic parameter groups and fixed parameters in the dynamic parameter group set are respectively input into the structural simulation model, and the internal quantum efficiency corresponding to each dynamic parameter group is simulated and calculated;
[0025] The dynamic parameter group with the maximum internal quantum efficiency within is used as the optimal dynamic parameter group to prepare a photoelectric chip structure with a high internal quantum efficiency.
[0026] A further optimization scheme is that the dynamic parameters include: the thickness and material of the second replacement layer (including the thickness and material of the first-level replacement layer and the thickness and material of the second-level replacement layer); the position (indicating which specific quantum barrier layer is replaced and inserted with the first replacement layer), quantity (indicating the total number of quantum barrier layers replaced and inserted with the first replacement layer), thickness and material of the first replacement layer; and the molar fraction x of Al in the electron blocking layer.
[0027] A further optimization scheme is that the structure simulation model simulates the photoelectric chip structure based on the structure parameters and analyzes the energy band structure and carrier behavior on the basis of quantum mechanics; the structure simulation model includes SiLENSe software, Crosslight software, C0MS0L Multiphysics software or Nextnano software.
[0028] A further optimization scheme is that the structure parameters of the photoelectric chip structure are input into the parameter combination model, and the dynamic parameters are adjusted according to the unit adjustment amount to combine multiple dynamic parameter group sets, including the method:
[0029] Based on the structure parameters of the photoelectric chip structure, multiple dynamic parameter groups are combined according to the following formula:
[0030]
[0031] Among them, Z is the internal quantum efficiency evaluation parameter, a is the first influence coefficient, b is the second influence coefficient; c is the third influence coefficient, c > 1; v represents the total number of quantum barrier layers replaced and inserted with the first replacement layer; ve represents the total number of quantum barrier layers;
[0032] A preset evaluation parameter threshold Ze is set, and the dynamic parameter groups with the internal quantum efficiency evaluation parameter Z < Ze are deleted to obtain the optimal parameter group set
[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0034] The present invention provides a high internal quantum efficiency optoelectronic chip structure and its design method. For AlGaN deep ultraviolet optoelectronic chip structures for wavelengths less than 300nm, based on the traditional aluminum gallium nitride (AlGaN) optoelectronic chip structure, improvements are made in structure and design method. By replacing and inserting a first replacement layer in part or all of the quantum barrier layers while keeping the thickness of the quantum barrier layer constant; and replacing and inserting a second replacement layer in the electron blocking layer while keeping the thickness of the electron blocking layer constant, the improved optoelectronic chip structure increases the quantum barrier band barrier height and reduces the effective hole barrier height, greatly improving the radiative recombination efficiency of the active region, thereby effectively improving the internal quantum efficiency and luminous efficiency of the AlGaN deep ultraviolet optoelectronic chip structure. In addition, this solution also provides a specific design method for an optoelectronic chip structure with high internal quantum efficiency. By adjusting the dynamic parameters according to the unit adjustment amount in the parameter combination model, multiple dynamic parameter group sets are combined, and only the dynamic parameter group sets are simulated and calculated to determine the optimal dynamic parameter group; avoiding the simulation and calculation of a large number of parameters, improving the production efficiency of optoelectronic chip structures with high internal quantum efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:
[0036] Figure 1 Schematic diagram of the optoelectronic chip structure with high internal quantum efficiency;
[0037] Figure 2 Schematic diagram of the multi-quantum well active layer structure;
[0038] Figure 3 Schematic diagram of the electron blocking layer structure;
[0039] Figure 4 A schematic diagram of a process for designing a photoelectric chip structure with high internal quantum efficiency;
[0040] Figure 5 Schematic diagram of the internal quantum efficiency of optoelectronic chip structure A and the internal quantum efficiency of optoelectronic chip structure B changing with current;
[0041] Figure 6 Schematic diagram of the internal quantum efficiency of optoelectronic chip structure A and the optical output power of optoelectronic chip structure B varying with current;
[0042] Figure 7 Schematic diagram of electron blocking layer structure A;
[0043] Figure 8 Schematic diagram of the internal quantum efficiency of the optoelectronic chip structures a, b, and c changing with current;
[0044] Figure 9 Schematic diagram of the optical output power of optoelectronic chip structures a, b, and c varying with current.
[0045] In the attached figure:
[0046] 1-substrate layer, 2-buffer layer, 3-multi-quantum well active layer, 31-quantum well layer, 32-quantum barrier layer, 33-first substitution layer, 4-electron blocking layer, 41-primary substitution layer, 42-secondary substitution layer, 5-P-type layer, 6-N-type layer; DETAILED DESCRIPTION
[0047] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.
[0048] Deep ultraviolet LED laser technology is not mature, and its internal quantum efficiency is much lower than that of mature nitride blue LED chip structures. In particular, in ultraviolet lasers, the wavelength of aluminum gallium nitride (AlGaN) materials is typically designed to be within the range of 200 to 365 nanometers, while the error of AlGaN deep ultraviolet optoelectronic chip structures with wavelengths less than 300nm is generally less than 10%, which is difficult to meet market demand. In view of this, the present invention provides the following embodiments to solve the above technical problems:
[0049] Example 1
[0050] This embodiment provides an optoelectronic chip structure with high internal quantum efficiency, comprising: a buffer layer, an N-type layer, a multi-quantum well active layer, an electron blocking layer, and a P-type layer stacked sequentially on a substrate layer;
[0051] The multi-quantum well active layer is formed by alternating and stacking n quantum barrier layers of the same material and thickness and n-1 quantum well layers of the same material and thickness;
[0052] When the thickness of the quantum barrier layer remains constant, a first replacement layer is inserted into part or all of the quantum barrier layer;
[0053] While the thickness of the electron blocking layer remains constant, a second replacement layer is inserted into the electron blocking layer.
[0054] The optoelectronic chip structure provided in this embodiment is improved on the basis of the conventional AlGaN deep ultraviolet LED structure; the first replacement layer and the second replacement layer are respectively inserted into the quantum barrier layer and the electron blocking layer; Figure 1 As shown, the optoelectronic chip structure includes: a buffer layer 2, an N-type layer 6, a multi-quantum well active layer 3, an electron blocking layer 4 and a P-type layer 5 stacked in sequence on a substrate layer 1; wherein the multi-quantum well active layer 3 is composed of six quantum barrier layers 32 and five quantum well layers 31 stacked in an alternating manner; a first replacement layer and a second replacement layer are respectively inserted into the quantum barrier layer and the electron blocking layer; the specific thickness position of the first replacement layer / the second replacement layer, as well as the structural parameters of the first replacement layer and the second replacement layer are determined according to the optoelectronic chip structure design method.
[0055] The position where the second replacement layer is replaced and inserted into the electron blocking layer includes: the second replacement layer is completely replaced and inserted above the electron blocking layer, the second replacement layer is completely replaced and inserted below the electron blocking layer, or the second replacement layer is symmetrically replaced and inserted above and below the electron blocking layer respectively.
[0056] The first replacement layer is inserted into the middle of the quantum barrier layer, and the center of the first replacement layer 33 overlaps with the center of the quantum barrier layer. Figure 2 As shown, in this embodiment, the center of each quantum barrier layer 32 is replaced by a first replacement layer 33.
[0057] In this embodiment, the substrate layer is a sapphire layer with a thickness of 400 μm; the buffer layer is an AlN buffer layer with a thickness of 2000 nm;
[0058] The N-type layer is 200nm thick n-Al 0.3s Ga 0.65 N layer; the doping concentration of n-type dopant is 5×10 18 cm- 3 ;
[0059] The multi-quantum well active layer includes 6 quantum barrier layers and 5 quantum well layers; the quantum barrier layer is Al2O3 with a thickness of 15 nm. 0.65 Ga 0.35 N layer; the quantum well layer is Al with a thickness of 2nm 0.35 Ga 0.65 N-layer;
[0060] The P-type layer is p-Al with a thickness of 200nm. 0.45 Ga 0.55 N layer; the doping concentration of p-type dopant is 5×10 19 cm -3 .
[0061] The electron blocking layer is 100 nm thick Al x Ga 1-x N layer; x is the molar fraction of Al in the electron blocking layer; 0.2 <x<0.8;
[0062] The second replacement layer includes a primary replacement layer 41 and a secondary replacement layer 42; the primary replacement layer 41 is Al x1 Ga (1-x1) N layer; the secondary replacement layer 42 is Al x2 Ga (1-x2 )N layer; where x1 is the molar fraction of Al in the primary substitution layer; x2 is the molar fraction of Al in the secondary substitution layer; x>x1>x2;
[0063] like Figure 3 As shown, two identical primary replacement layers 41 are respectively inserted above and below the electron blocking layer 4 ; and two identical secondary replacement layers 42 are respectively inserted at the surface positions of the two primary replacement layers 41 .
[0064] The electron blocking layer is an Al layer with a thickness of 100 nm. 0.65 Ga 0.35 N layer; the first replacement layer is Al with a thickness of 5nm 0.68 Ga 0.32 N layer; the primary replacement layer is 15nm thick Al 0.6 Ga0.4N layer, the secondary replacement layer is 15nm thick Al 0.55 Ga 0.45 N layer; the thickness of the remaining electron blocking layer after replacement is 40nm.
[0065] Example 2
[0066] This embodiment provides a method for designing an optoelectronic chip structure, which is used to determine the optoelectronic chip structure with high internal quantum efficiency, such as Figure 4 As shown, including methods:
[0067] Step 1: Setting the structural parameters and structural conditions of the optoelectronic chip structure, wherein the structural parameters include fixed parameters, dynamic parameters and unit adjustment amounts;
[0068] The dynamic parameters include: the thickness and material of the second replacement layer (including the thickness and material of the first replacement layer, and the thickness and material of the second replacement layer); the replacement position (referring to which specific quantum barrier layer replaces the first replacement layer), quantity (referring to the total number of quantum barrier layers that replace the first replacement layer), thickness and material of the first replacement layer; and the molar fraction x of Al in the electron blocking layer.
[0069] Fixed parameters include data such as the material, thickness, and doping concentration of the substrate layer, buffer layer, N-type layer, multi-quantum well active layer, electron blocking layer, and P-type layer in addition to the above-mentioned dynamic parameters. They also include parameters such as band offset ratio, dislocation density, Shockley-Reed-Hall (SRH) recombination lifetime, operating temperature, and Auger recombination coefficient.
[0070] Step 2: Input the structural parameters of the optoelectronic chip structure into the parameter combination model, and adjust the dynamic parameters according to the unit adjustment amount to combine multiple sets of dynamic parameter groups; the specific method of this step includes:
[0071] Based on the structural parameters of the optoelectronic chip structure, combine multiple sets of dynamic parameters according to the following formula:
[0072]
[0073] where, Z is the internal quantum efficiency evaluation parameter, a is the first influence coefficient, b is the second influence coefficient; c is the third influence coefficient, c > 1; v represents the total number of quantum barrier layers where the first replacement layer is replaced and inserted; ve represents the total number of quantum barrier layers;
[0074] Preset an evaluation parameter threshold Ze, and delete the dynamic parameter groups with the internal quantum efficiency evaluation parameter Z < Ze to obtain the optimal parameter group set. When combining the dynamic parameter groups, the above formula can be solved by methods such as the projection gradient method and the stepwise linearization method. In the specific solution process, the dynamic parameters are adjusted sequentially according to the preset unit adjustment amount. For example, each time during the calculation, the thickness of the second replacement layer is superimposed according to the unit adjustment amount of 1 nm, and the molar quantity of the material AL in the first-level replacement layer / second-level replacement layer is superimposed according to the unit adjustment amount of 0.01, and so on until the dynamic parameter groups that meet the requirements of the internal quantum efficiency evaluation parameter are found.
[0075] Step 3: Input the dynamic parameter groups and fixed parameters in the dynamic parameter group set into the structure simulation model respectively, and simulate and calculate the internal quantum efficiency corresponding to each dynamic parameter group;
[0076] The structure simulation model simulates the optoelectronic chip structure according to the structural parameters, and analyzes the energy band structure and carrier behavior based on quantum mechanics; the structure simulation model includes SiLENSe software, Crosslight software, COMSOL Multiphysics software or Nextnano software.
[0077] The simulation software focusing on quantum structures and optoelectronic devices includes Crosslight software or Nextnano software, and these software can also be used to simulate the optoelectronic chip structure and perform corresponding quantum mechanics calculations; in this solution, SiLENSe software is used as the structure simulation model. Since SiLENSe software fully considers the characteristics of various semiconductor materials, such as spontaneous polarization, piezoelectric polarization, dislocation density, and acceptor activation rate, etc., SiLENSe software can meet the requirements of repeatedly adjusting the parameters of the epitaxial structure, the bias voltages on both sides, etc. during the process of combining the dynamic parameter group set, so as to obtain simulation results such as the energy band structure diagram, the carrier concentration and matching degree inside the structure, the radiation and non-radiative recombination efficiency, the light emission efficiency, the electric field distribution, and the emission spectrum of the LED.
[0078] Step 4: Using the dynamic parameter group with the highest internal quantum efficiency as the optimal dynamic parameter group to prepare a high internal quantum efficiency optoelectronic chip structure.
[0079] Example 4
[0080] To verify the feasibility of the method of the present invention, the structure of the optoelectronic chip B is input into the structural simulation model in this embodiment: the substrate layer is a sapphire layer with a thickness of 400 μm; the buffer layer is an AlN buffer layer with a thickness of 2000 nm; the N-type layer is an n-AlN layer with a thickness of 200 nm. 0.35 Ga 0.65 N layer; the doping concentration of n-type dopant is 5×10 18 cm -3 The multi-quantum well active layer includes 6 quantum barrier layers and 5 quantum well layers; the quantum barrier layer is 15nm thick Al 0.65 Ga 0.35 N layer; the quantum well layer is Al with a thickness of 2nm 0.35 Ga 0.65 N layer; P-type layer is p-Al with a thickness of 200nm 0.45 Ga 0.55 N layer; the doping concentration of p-type dopant is 5×10 19 cm -3 Two identical primary replacement layers 41 are inserted above and below the electron blocking layer 4; two identical secondary replacement layers 42 are inserted above and below the two primary replacement layers 41; the electron blocking layer is Al with a thickness of 100 nm. 0.65 Ga 0.35 N layer; the first replacement layer is Al with a thickness of 5nm 0.68 Ga 0.32 N layer; the primary replacement layer is 15nm thick Al 0.6 Ga 0.4 N layer, the secondary replacement layer is 15nm thick Al 0.55 Ga 0.45 N layer; the thickness of the remaining electron blocking layer after replacement is 40nm.
[0081] In this embodiment, the A optoelectronic chip structure is input into the structural simulation model: there is no primary replacement layer 41, secondary replacement layer 42 and first replacement layer, and the remaining parameters are consistent with the B optoelectronic chip structure. The schematic diagram of the relationship between the internal quantum efficiency and light output power of the B optoelectronic chip structure and the A optoelectronic chip structure as the current changes is shown in the figure. Figure 5 and Figure 6 As shown by Figure 5It can be seen that as the current increases, the internal quantum efficiency of the A photoelectric chip structure and the B photoelectric chip structure both increase; when the current is 80mA, the internal quantum efficiency of the A photoelectric chip structure and the B photoelectric chip structure both reach a peak value; the peak internal quantum efficiency of the A photoelectric chip structure is 34.23%, and the peak internal quantum efficiency of the B photoelectric chip structure is 45.56%, which is 11.33% higher than that of the A photoelectric chip structure; Figure 6 It can be seen that within a certain current range, as the current increases, the optical output power of the optoelectronic chip structure A and the optical output power of the optoelectronic chip structure B both increase linearly; when the current is within 200mA, the optical output power of the optoelectronic chip structure A is 21.55mW; the optical output power of the optoelectronic chip structure B is 26.21mW, which is 21.62% higher than that of sample A.
[0082] In addition, if Figure 4 As shown, this embodiment further provides a multi-quantum well active layer structure, wherein only the centers of the first quantum barrier layer, the third quantum barrier layer, and the fifth quantum barrier layer are replaced by the first replacement layer.
[0083] Take the A optoelectronic chip structure as the a optoelectronic chip structure;
[0084] by Figure 2 The centers of all quantum barrier layers shown are replaced by the first replacement layer, and the other structures are the same as the optoelectronic chip structure A, and the optoelectronic chip structure is the optoelectronic chip structure B; Figure 4 As shown, only the centers of the first quantum barrier layer, the third quantum barrier layer and the fifth quantum barrier layer are replaced with the first replacement layer, A optoelectronic chip structure, and the optoelectronic chip structure formed is b optoelectronic chip structure.
[0085] The photoelectric chip structure a, photoelectric chip structure b and photoelectric chip structure c are simulated, and the relationship between the internal quantum efficiency and light output power as the current changes is shown in the figure. Figure 7 and Figure 8 As shown, according to Figure 7 and Figure 8 It can be seen that the optoelectronic chip structure c has the best internal quantum efficiency and light output power, the optoelectronic chip structure b has the second best internal quantum efficiency and light output power, and the optoelectronic chip structure a (traditional structure) has the worst internal quantum efficiency and light output power. The improved structure can increase the quantum barrier energy band barrier height while reducing the effective hole barrier height, greatly improving the radiative recombination efficiency of the active region, thereby effectively improving the internal quantum efficiency and luminous efficiency of the A1GaN deep purple optoelectronic chip structure;
[0086] This solution targets the AlGaN deep ultraviolet optoelectronic chip structure for wavelengths less than 300nm. Based on the traditional aluminum gallium nitride (AlGaN) optoelectronic chip structure, it makes structural and design method improvements. By replacing the first replacement layer in some or all of the quantum barrier layers while keeping the thickness of the quantum barrier layer constant, and replacing the second replacement layer in the electron blocking layer while keeping the thickness of the electron blocking layer constant, the improved optoelectronic chip structure increases the quantum barrier band barrier height while reducing the effective hole barrier height, greatly improving the radiative recombination efficiency of the active region, thereby effectively improving the internal quantum efficiency and luminous efficiency of the AlGaN deep ultraviolet optoelectronic chip structure. In addition, this solution also provides a specific design method for optoelectronic chip structures with high internal quantum efficiency. Through the parameter combination model, the dynamic parameters are adjusted according to the unit adjustment amount to combine multiple dynamic parameter group sets. Only the dynamic parameter group sets are simulated and calculated to determine the optimal dynamic parameter group. This avoids the simulation and calculation of a large number of parameters and improves the production efficiency of optoelectronic chip structures with high internal quantum efficiency.
[0087] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A photoelectric chip structure with high internal quantum efficiency, characterized in that: include: A buffer layer, an N-type layer, a multi-quantum well active layer, an electron blocking layer and a P-type layer are sequentially stacked on the substrate layer; The multi-quantum well active layer is formed by alternating and stacking n quantum barrier layers of the same material and thickness and n-1 quantum well layers of the same material and thickness; When the thickness of the quantum barrier layer remains constant, a first replacement layer is inserted into part or all of the quantum barrier layer; While the thickness of the electron blocking layer remains constant, inserting a second replacement layer into the electron blocking layer; The second replacement layer is inserted into the electron blocking layer at a position where the second replacement layer is symmetrically inserted above and below the electron blocking layer; The first replacement layer is inserted into the middle position of the quantum barrier layer, and the center of the first replacement layer overlaps with the center of the quantum barrier layer; The electron blocking layer is an Al layer with a thickness of 100 nm. x Ga 1-x N layer; x is the mole fraction of Al in the electron blocking layer; 0.2<x<0.8; The second replacement layer includes a primary replacement layer and a secondary replacement layer; the primary replacement layer is Al x1 Ga (1-x1) N layer; the secondary replacement layer is Al x2 Ga (1-x2) N layer; where x1 is the mole fraction of Al in the primary substitution layer; x2 is the mole fraction of Al in the secondary substitution layer; x>x1>x2; Two identical primary replacement layers are respectively inserted above and below the electron blocking layer; and two identical secondary replacement layers are respectively inserted at the surface positions of the two primary replacement layers.
2. The optoelectronic chip structure with high internal quantum efficiency according to claim 1, characterized in that: The substrate layer is a sapphire layer with a thickness of 400 μm; the buffer layer is an AlN buffer layer with a thickness of 2000 nm; The N-type layer is an n-Al layer with a thickness of 200 nm. 0.35 Ga 0.65 N layer; the doping concentration of n-type dopant is 5×10 18 cm -3 ; The multi-quantum well active layer includes 6 quantum barrier layers and 5 quantum well layers; the quantum barrier layer is Al with a thickness of 15nm. 0.65 Ga 0.35 N layer; the quantum well layer is Al with a thickness of 2nm 0.35 Ga 0.65 N-layer; The P-type layer is a p-Al layer with a thickness of 200 nm. 0.45 Ga 0.55 N layer; the doping concentration of p-type dopant is 5×10 19 cm -3 .
3. The optoelectronic chip structure with high internal quantum efficiency according to claim 1, characterized in that: The electron blocking layer is an Al layer with a thickness of 100 nm. 0.65 Ga 0.35 N layer; the first replacement layer is Al with a thickness of 5nm 0.68 Ga 0.32 N layer; the primary replacement layer is 15nm thick Al 0.6 Ga 0.4 N layer, the secondary replacement layer is 15nm thick Al 0.55 Ga 0.45 N layers.
4. A method for designing an optoelectronic chip structure, characterized in that: A method for determining an optoelectronic chip structure with high internal quantum efficiency as claimed in claim 2 or 3, comprising: Setting structural parameters and structural conditions of the optoelectronic chip structure, wherein the structural parameters include fixed parameters, dynamic parameters and unit adjustment amounts; Inputting the structural parameters of the optoelectronic chip structure into the parameter combination model, and adjusting the dynamic parameters according to the unit adjustment amount to combine multiple dynamic parameter group sets; The dynamic parameter groups and fixed parameters in the dynamic parameter group set are respectively input into the structural simulation model, and the internal quantum efficiency corresponding to each dynamic parameter group is simulated and calculated; A high internal quantum efficiency optoelectronic chip structure is prepared by taking the dynamic parameter group with the highest internal quantum efficiency as the optimal dynamic parameter group; The dynamic parameters include: the thickness and material of the second replacement layer; the replacement position, quantity, thickness and material of the first replacement layer; the molar fraction x of Al in the electron blocking layer; The structural parameters of the optoelectronic chip structure are input into the parameter combination model, and the dynamic parameters are adjusted according to the unit adjustment amount to combine multiple dynamic parameter group sets, including the following method: Based on the structural parameters of the optoelectronic chip structure, multiple dynamic parameter groups are combined according to the following formula: ; Among them, Z is the internal quantum efficiency evaluation parameter, is the first influence coefficient, b is the second influence coefficient; c is the third influence coefficient, c>1; v represents the total number of quantum barrier layers inserted to replace the first replacement layer; represents the total number of quantum barriers; Preset the evaluation parameter threshold Ze, delete the dynamic parameter group with internal quantum efficiency evaluation parameter Z < Ze to obtain the optimal parameter group set; The structural simulation model simulates the optoelectronic chip structure according to the structural parameters and analyzes the band structure and carrier behavior based on quantum mechanics; the structural simulation model includes SiLENSe software, Crosslight software, COMSOL Multiphysics software or Nextnano software.
Citation Information
Patent Citations
AlGaN-based ultraviolet LED epitaxial wafer structure and preparation method thereof
CN109616559A
Semiconductor layer sequence
CN109690793A
Capacitor design method and device, electronic equipment, medium and program product
CN116401993A