Wide-spectrum indium gallium arsenic battery based on front contact and battery array assembly

Abstract

The utility model discloses a wide-spectrum indium gallium arsenic battery based on a front contact type and a battery array assembly. The wide-spectrum indium gallium arsenic battery based on the front contact type comprises a substrate, a buffer layer and a transition layer which are sequentially arranged from top to bottom, the transition layer is provided with a P-N junction layer and a negative electrode, the P-N junction layer is provided with a window layer, the window layer is provided with a front contact layer, and the front contact layer is provided with a positive electrode and an antireflection layer. According to the structure of a traditional indium gallium arsenic battery, a positive electrode and a negative electrode are arranged on the front face and the back face respectively, the positive electrode and the negative electrode of the front contact type indium gallium arsenic battery are both arranged on the front face of the battery, and when the battery of the structure is manufactured into an array assembly, the distance between adjacent batteries can be reduced to 50 micrometers, and the battery efficiency is improved. The problems of short circuit and the like caused by large distance between adjacent batteries when the traditional indium gallium arsenic battery is prepared into an array are solved; the battery assembly prepared by the method provided by the utility model is large in effective utilization area, and damaged batteries in the assembly are convenient to replace.

Description

Technical Field

[0001] The utility model belongs to the technical field of infrared optoelectronic conversion devices, and particularly relates to an indium gallium arsenide (InGaAs) battery and a battery array component based on a front-contact type and capable of absorbing near-infrared band spectra. Background Technique

[0002] Indium gallium arsenide (InGaAs) battery is a commonly used optoelectronic conversion device, and indium phosphide (InP) material is usually used as a substrate in its preparation process. According to the introduction of Patent CN102623575A and Patent CN116454146A, InGaAs / InP battery grows InGaAs material on the InP substrate through metalorganic chemical vapor deposition (MOCVD) or molecular beam epitaxy growth technology (MBE), and can adjust the proportion of various elements therein as needed, so as to prepare an InGaAs battery with a bandgap width ranging from 0.5 to 0.7 eV. This special design of the bandgap width enables the spectral response of the InGaAs battery to be extended up to 2500 nm at most. Due to its excellent optoelectronic performance, the InGaAs battery can play an important role in many fields.

[0003] In real engineering applications, multiple batteries should be formed into a battery component in a matrix form to meet the current and voltage requirements in actual applications. However, the current structures of InGaAs batteries are similar to the InGaAs battery used in the literature "Thermophotovoltaic efficiency of 40%" (authors LaPotin, etc., Nature magazine, 604, 287-291 (2022)), where the positive and negative electrodes of the battery are respectively placed on the front and back of the battery and make ohmic contact with the P-type and N-type semiconductor layers. Although this traditional structure performs well in the application of a single battery, it has significant defects when assembled into a multi-battery array component. Specifically: 1. Structural complexity: In a multi-battery array, the positive and negative electrodes of each battery need to be independently led out, which increases the manufacturing complexity and process difficulty of the battery array. 2. Reduction of the effective area of the array: Since the positive and negative electrodes are respectively located on the front and back of the battery, a solder strip is required to connect the front of one battery to the bottom of another battery when connecting adjacent batteries. To prevent short circuits, the distance between the batteries must be kept large, which not only increases the size of the array but also reduces the effective utilization area of the battery array and lowers the space utilization efficiency.

[0004] According to the introduction of Patent CN108649087B, in order to improve the effective utilization area of the battery array, some designs adopt the overlapping shingle module design. However, this design also has significant drawbacks: due to the large number of overlapping parts of the batteries in the overlapping shingle module design, it is easy to cause short circuits, and the batteries in the overlapping shingle module are usually connected in series, which means that if one of the batteries is damaged or its performance deteriorates, the performance of the entire module will be severely affected or even completely fail. This design makes it impossible to repair the module, reducing the overall lifespan and reliability of the system.

[0005] Therefore, the InGaAs batteries prepared by the prior art have the above limitations when making multi-battery array modules, and there is an urgent need for an improved structural design to overcome these problems. Summary of the Invention

[0006] Utility Model Objective: The objective of the present utility model is to provide a front-contact-based broadband InGaAs battery that is conducive to forming a battery array. In the present utility model, both the positive and negative electrodes of the battery are placed on the positive surface of the battery. Thus, when prepared into an array module, the gap between the batteries can be reduced to 50 μm, greatly improving the effective power generation area of the array. It effectively solves the problems such as easy short circuits and low effective utilization area of the array modules prepared by the traditional battery structure. Another objective of the present utility model is to provide a battery array module.

[0007] Technical Solution: The front-contact-based broadband indium gallium arsenide battery of the present utility model includes a substrate, a buffer layer, and a transition layer sequentially arranged from top to bottom; a P-N junction layer and a negative electrode are respectively provided on the transition layer, a window layer is provided on the P-N junction layer, a front contact layer is provided on the window layer, and a positive electrode and an antireflection layer are respectively provided on the front contact layer; wherein the negative electrode is not in contact with the base, the negative electrode is not in contact with the emitter, and the positive electrode is not in contact with the antireflection layer.

[0008] Further, the transition layer is composed of N InP x As 1-x transition layers.

[0009] Further, from bottom to top, the content of As in the N InP x As 1-x transition layers gradually increases from 0.05 to 0.3.

[0010] Further, the transition layer includes N-type InP 0.95 As 0.05 transition layer, N-type InP 0.9 As 0.1 transition layer, N-type InP 0.85 As 0.15 transition layer, N-type InP 0.8 As0.2 Intermediate layer, N-type InP 0.75 As 0.25 Intermediate layer, N-type InP 0.7 As 0.3 Intermediate layer.

[0011] Further, the substrate is an N-type indium phosphide substrate, the buffer layer is an N-type indium phosphide buffer layer, and the P-N junction layer is an In 0.68 Ga 0.32 As junction layer, and the window layer is an InP 0.7 As 0.3 window layer, and the front contact layer is an In 0.68 Ga 0.32 As front contact layer, and the antireflection layer is a silicon nitride thin film.

[0012] Further, the positive electrode material is Ti / Pt / Au.

[0013] Further, the negative electrode material is Au / Ni / Au.

[0014] On the other hand, the present utility model provides a battery array assembly, which is formed by arranging a plurality of the above-mentioned front-contact type broadband indium gallium arsenide batteries into a flat compact module.

[0015] Further, in the flat compact module, the negative electrodes and positive electrodes of adjacent batteries are connected by gold wires. On the other hand, the present utility model provides a preparation method for the above-mentioned front-contact type broadband indium gallium arsenide battery, including the following steps:

[0016] (1) Substrate treatment to obtain a treated substrate;

[0017] (2) Growing a buffer layer, a plurality of intermediate layers, a P-N junction layer, a window layer, a front contact layer, and an antireflection layer on the treated substrate in sequence to obtain indium gallium arsenide epitaxial material;

[0018] (3) Photolithographing positive and negative electrodes and grid line regions on the indium gallium arsenide epitaxial material, soaking and removing the antireflection layer in the electrode and grid line regions to expose a part of the front contact layer as the positive electrode contact region; etching away a part of the front contact layer, a part of the window layer, and a part of the P-N junction layer to expose a part of the intermediate layer as the negative electrode contact region;

[0019] (4) Evaporating a negative electrode on the intermediate layer and evaporating a positive electrode on the front contact layer; obtaining a broadband indium gallium arsenide battery.

[0020] Further, in step (1), the substrate treatment method is: sequentially placing the substrate in isopropyl alcohol, acetone, and alcohol for cleaning, removing oxides on the substrate surface with dilute hydrochloric acid; then placing it in water for cleaning, drying and baking after cleaning to obtain the treated substrate.

[0021] Further, in step (2), a buffer layer, a plurality of transition layers, a P-N junction layer, a window layer, a front contact layer, and a plurality of antireflection layers are sequentially grown by chemical vapor deposition.

[0022] Further, in step (3), the etching solution used for soaking and removing the antireflection layer includes hydrofluoric acid and ammonium fluoride; the etching solution used for etching away part of the front contact layer, part of the window layer, and part of the P-N junction layer includes phosphoric acid and hydrogen peroxide.

[0023] Further, in step (4), a negative electrode is deposited on the transition layer and a positive electrode is deposited on the front contact layer by electron beam evaporation.

[0024] On the other hand, the present utility model provides a preparation method for a battery array assembly. The front-contact wide-spectrum indium gallium arsenide batteries are arranged into a flat compact module, and the distance between the batteries is ensured to be controlled at about 50 μm. A gold wire bonder is used to weld the negative and positive electrodes of adjacent batteries through gold wires, and electrical performance tests are carried out to ensure the normal connection of the batteries.

[0025] Beneficial effects: Compared with the prior art, the present utility model has the following remarkable advantages: For the front-contact indium gallium arsenide battery of the present utility model, both the positive and negative electrodes are on the positive surface of the battery. When the batteries with this structure are prepared into an array assembly, the distance between adjacent batteries can be reduced to 50 μm, solving the problems such as large distance between adjacent batteries and easy short circuit when traditional indium gallium arsenide batteries are prepared into an array; the battery assembly prepared by the method of the present utility model has a large effective utilization area, and it is convenient to replace damaged batteries in the assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural diagram of the indium gallium arsenide epitaxial material and the antireflection layer of the present utility model.

[0027] Figure 2 It is an etching sectional view of the indium gallium arsenide battery of the present utility model.

[0028] Figure 3 It is a top view of the etched indium gallium arsenide battery of the present utility model.

[0029] Figure 4 It is a structural diagram of the front-contact indium gallium arsenide battery of the present utility model.

[0030] Figure 5 It is an assembly diagram of the front-contact indium gallium arsenide battery of the present utility model.

[0031] Figure 6 It is a structural diagram of the indium gallium arsenide battery in Comparative Example 1 of the present utility model.

[0032] Figure 7It is the diagram of the indium gallium arsenide battery module in Comparative Example 1 of the present utility model.

[0033] Figure 8 It is the diagram of the indium gallium arsenide battery module in Comparative Example 2 of the present utility model.

[0034] Figure 9 It is the external quantum efficiency diagram of the front-contact indium gallium arsenide battery of the present utility model and the indium gallium arsenide battery in Comparative Example 1, where curve a is the external quantum efficiency curve of the front-contact indium gallium arsenide battery with both positive and negative electrodes on the front side, curve b is the external quantum efficiency curve of the front-contact indium gallium arsenide battery with the positive and negative electrodes on the front and back sides respectively, and curve c is the external quantum efficiency curve of the indium gallium arsenide battery in Comparative Examples 1 and 2.

[0035] Reference numerals: 1, substrate; 2, buffer layer; 3, first transition layer; 4, second transition layer; 5, third transition layer; 6, fourth transition layer; 7, fifth transition layer; 8, sixth transition layer; 9, base; 10, emitter; 11, window layer; 12, front contact layer; 13, first antireflection layer; 14, second antireflection layer; 15, positive electrode part; 16, grid line part; 17, negative electrode part; 18, positive electrode; 19, negative electrode; S1, indium gallium arsenide epitaxial material; 20, gold wire; 21, bottom plate; 22, gap; 23, solder strip. Detailed Description of the Specific Embodiments

[0036] The present utility model uses a metal organic chemical vapor deposition system to perform epitaxial growth of an indium gallium arsenide battery on a semiconductor indium phosphide substrate, uses a PECVD chemical vapor deposition system to prepare an antireflection layer, etches the front-contact electrode area based on chemical wet etching technology, and uses electron beam evaporation to prepare the electrodes of the indium gallium arsenide battery.

[0037] An embodiment of the present utility model provides a broadband indium gallium arsenide battery based on a front-contact type, which includes a substrate, a buffer layer, and a transition layer sequentially arranged from top to bottom; a P-N junction layer and a negative electrode are respectively arranged on the transition layer, a window layer is arranged on the P-N junction layer, a front contact layer is arranged on the window layer, and a positive electrode and an antireflection layer are respectively arranged on the front contact layer; wherein the negative electrode does not contact the base, the negative electrode does not contact the emitter, and the positive electrode does not contact the antireflection layer. The P-N junction layer is composed of an N-type base and a P-type emitter.

[0038] The embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

[0039] Example 1:

[0040] As Figures 1-4As shown in the figure, this embodiment provides a front-contact-based broadband indium gallium arsenide cell, which includes a substrate 1, a buffer layer 2, a first transition layer 3, a second transition layer 4, a third transition layer 5, a fourth transition layer 6, a fifth transition layer 7, and a sixth transition layer 8 stacked in sequence from top to bottom. A base electrode 9 and a negative electrode 19 are provided on the sixth transition layer 8. An emitter 10, a window layer 11, and a front contact layer 12 are stacked in sequence on the base electrode 9. A positive electrode 18 and a first antireflection layer 13 are respectively provided on the front contact layer 12. A second antireflection layer 14 is provided on the first antireflection layer 13. A grid line part 16 is provided on the second antireflection layer 14. Among them, both the positive electrode 18 and the negative electrode 19 are located on the front side of the broadband indium gallium arsenide cell and are respectively placed on different sides of the front side of the broadband indium gallium arsenide cell.

[0041] This embodiment provides a preparation method for the above-mentioned front-contact-based broadband indium gallium arsenide cell, including the following steps:

[0042] (1) Substrate treatment: An N-type indium phosphide wafer with a sulfur (S) concentration of 4×10 18 cm -3 , <100> crystal orientation is successively placed in isopropyl alcohol, acetone, and alcohol for cleaning, and cleaned in each solution for 5 minutes. Then, a 5% dilute hydrochloric acid is used to remove the oxide on the surface of the indium phosphide wafer. Finally, it is cleaned in deionized water, dried with nitrogen, and baked on a hot plate at 180 °C for 10 minutes to remove the surface water vapor;

[0043] (2) Epitaxial growth: As Figure 1 shown, the cleaned and dried indium phosphide (InP) substrate 1 is placed on the substrate stage in the reaction chamber of the chemical vapor deposition equipment, and an N-type indium phosphide (InP) buffer layer 2 with a thickness of 400 nm, a silicon (Si) carrier concentration of 5×10 -17 cm -3 ; 400 nm of N-type InP 0.95 As 0.05 the first transition layer 3, a silicon (Si) carrier concentration of 5×10 -17 cm -3 ; 400 nm of N-type InP 0.9 As 0.1 the second transition layer 4, a silicon (Si) carrier concentration of 5×10 -17 cm -3 ; 400 nm of N-type InP 0.85 As 0.15 the third transition layer 5, a silicon (Si) carrier concentration of 5×10 -17 cm -3 ; 400 nm of N-type InP 0.8 As 0.2 the fourth transition layer 6, a silicon (Si) carrier concentration of 5×10-17 cm -3 ; N-type InP of 400 nm 0.75 As 0.25 The fifth transition layer 7, with a silicon (Si) carrier concentration of 5×10 -17 cm -3 ; N-type InP of 1000 nm 0.7 As 0.3 The sixth transition layer 8, with a tellurium (Te) carrier concentration of 1×10 -19 cm -3 ; N-type In of 300 nm 0.68 Ga 0.32 The As base 9, with a tellurium (Te) carrier concentration of 3×10 -18 cm -3 ; P-type In of 3000 nm 0.68 Ga 0.32 The As emitter 10, with a zinc (Zn) carrier concentration of 2×10 -17 cm -3 ; InP of 500 nm 0.7 As 0.3 The window layer 11, with a zinc (Zn) carrier concentration of 2×10 -18 cm -3 ; In of 50 nm 0.68 Ga 0.32 The As front contact layer 12, with a zinc (Zn) carrier concentration of 3×10 -19 cm -3 .

[0044] (3) Preparation of the antireflection layer: Place the epitaxial indium gallium arsenide cell into the PECVD chemical vapor deposition chamber, and deposit a silicon nitride antireflection layer on the front surface of the cell. First, evacuate the chamber until the vacuum degree reaches below 1e -5 Pa. Then, heat the chamber to 250 °C, and introduce SiH4 gas with a flow rate controlled at 30 sccm and NH3 gas with a flow rate controlled at 50 sccm. Adjust the radio frequency power supply to 15 W. At this time, the chemical reaction 3SiH4 + 4NH3 → Si3N4 + 12H2 will occur in the chamber, and deposit a silicon nitride thin film with a refractive index n of 2.3 on the front surface of the indium gallium arsenide cell as the first antireflection layer 13 at a deposition rate of 13 nm / min for 115 nm. Then, increase the radio frequency power supply to 100 W. At this time, the refractive index n of the silicon nitride thin film deposited on the front surface of the indium gallium arsenide cell as the second antireflection layer 14 is 1.8, and the deposition rate is 20 nm / min for 165 nm. The indium gallium arsenide epitaxial material S1 is prepared;

[0045] (4) Preparation of the front contact electrode: As Figure 2 and 3As shown, single-step photolithography is used to develop the positive electrode part 15, the gate line part 16, and the negative electrode part 17, and the first anti-reflection layer 13 and the second anti-reflection layer 14 of these three parts are etched away. The specific etching method is wet etching, and the selected etching solution is hydrofluoric acid (HF): ammonium fluoride (NH4F): deionized water (H2O) = 3mL: 6g: 10mL, and the etching rate at room temperature is 0.21μm / min; re-smearing glue is used for photolithography and the negative electrode part 17 is developed, and the In of this part is 0.68 Ga 0.32 As front contact layer 12, InP 0.7 As 0.3 Window layer 11, P-type In 0.68 Ga 0.32 As emitter 10, N-type In 0.68 Ga 0.32 The As base 9 is etched away, and a phosphoric acid-based etching solution is selected, phosphoric acid (H3PO4): hydrogen peroxide (H2O2): deionized water (H2O) = 5mL: 2mL: 40mL, and the etching rate at room temperature is 0.57μm / min;

[0046] The positive electrode part 15, the gate line part 16 and the negative electrode part 17 are first developed by photolithography, and the positive electrode and the gate line are prepared by electron beam evaporation technology. The etched InGaAs battery is placed in an electron beam coating machine, and the chamber is first evacuated to a vacuum degree of 1e -5 Pa, turn on the filament and electron beam power supply, adjust the beam intensity to 50W / cm, melt the metal titanium (Ti) to be evaporated, open the sample baffle, and adjust the beam intensity to 25W / cm 2 , evaporation of 20nm titanium (Ti), the evaporation rate is Then turn off the electron beam power supply and filament, replace the evaporated sample with platinum (Pt), and evaporate 40nm of platinum (Pt) with a beam intensity of 30W / cm 2 , the evaporation rate is Finally, 4 μm of gold (Au) was evaporated with a beam intensity of 40 W / cm 2 , the evaporation rate is Then, a stripping process is used to remove the area protected by the photoresist. Figure 4 As shown, the positive electrode 18 and the negative electrode 19 of the battery are both distributed on the front side of the battery.

[0047] like Figure 5As shown in the figure, this embodiment provides a method for preparing a battery array component. When preparing the battery array component, the positive and negative electrodes of adjacent batteries are aligned and placed on the same side, and are welded together with a gold wire 20. At the same time, the back surface of the battery is welded to an aluminum nitride (AlN) ceramic bottom plate 21. Since the positive and negative electrodes of the battery are both on the upper surface of the battery, the welding of the battery array is relatively easy, and the minimum distance of the gap 22 between adjacent batteries can reach 50 μm.

[0048] By using a quantum efficiency tester for measurement, the external quantum efficiency of the battery can be obtained. Figure 9 In the figure, curves a and b are the quantum efficiency curves measured from the positive and negative electrodes on the front side of the battery and the quantum efficiency curves measured from both the front and back sides respectively. It can be found that the front-contact indium gallium arsenide battery prepared by the present utility model has good spectral responsivity in the near-infrared band, and the quantum efficiency can reach up to 83%. Moreover, this design with both positive and negative electrodes on the front side will not affect the collection of carriers in the battery.

[0049] Comparative Example 1:

[0050] In this comparative example, the substrate treatment, epitaxial growth process, and preparation of the antireflection layer are the same as those in Example 1. As Figure 6 shown in the figure, during the etching process, only the double-layer silicon nitride thin films at the positive electrode part 15 and the grid line part 16 are etched away. Then, by using the lift-off process, 20 nm of titanium (Ti), 40 nm of platinum (Pt), and 4 μm of gold (Au) are evaporated on the positive electrode part 15 and the grid line part 16. Finally, on the back surface of the battery, by using the electron beam evaporation technique, 14 nm of gold, 14 nm of germanium, 14 nm of gold, 10 nm of nickel, and 3 μm of gold are evaporated in sequence to prepare the negative electrode 19. The indium gallium arsenide battery prepared in this way is a battery with the positive and negative electrodes on the front and back sides of the battery respectively;

[0051] As Figure 7 shown in the figure, when this conventional indium gallium arsenide battery is prepared into an array component, the positive electrode 18 of the battery needs to be welded to the negative electrode 19 on the back surface of its adjacent battery through a solder strip 23. At the same time, the negative electrode 19 of the battery is welded to the aluminum nitride (AlN) ceramic bottom plate 21. Considering that the solder strip for connecting the positive and negative electrodes between adjacent batteries needs to pass through the side of the indium gallium arsenide battery, in order to prevent the battery from being short-circuited by the solder strip, the distance of the gap 22 between adjacent batteries is generally greater than 5 mm.

[0052] Figure 9 In the figure, curve c is the external quantum efficiency curve of the indium gallium arsenide battery prepared in this comparative example, and the highest quantum efficiency is 79%, which is slightly lower than the quantum efficiency of the front-contact indium gallium arsenide battery.

[0053] Comparative Example 2:

[0054] In this comparative example, the prepared indium gallium arsenide battery is the same as that in Comparative Example 1. The shingling method is adopted when preparing the array component. As shown in the attached Figure 8 figure, the negative electrode 19 of the battery is welded to the positive electrode 18 of the adjacent battery, and at the same time, the negative electrodes 19 on the back of all the batteries are welded to the aluminum nitride (AlN) ceramic bottom plate 21.

Claims

1. A front-contact wide-spectrum indium gallium arsenide battery, characterized in that, It includes a substrate, a buffer layer, and a transition layer arranged successively from top to bottom; a P-N junction layer and a negative electrode are respectively provided on the transition layer, a window layer is provided on the P-N junction layer, a front contact layer is provided on the window layer, and a positive electrode and an antireflection layer are respectively provided on the front contact layer; wherein the negative electrode is not in contact with the base, the negative electrode is not in contact with the emitter, and the positive electrode is not in contact with the antireflection layer.

2. The front-contact-based broadband indium gallium arsenide cell according to claim 1, wherein The transition layer consists of N InP x As 1-x transition layers.

3. The front-contact-based broadband indium gallium arsenide cell according to claim 1, characterized in that, The substrate is an N-type indium phosphide substrate, the buffer layer is an N-type indium phosphide buffer layer, and the antireflection layer is a silicon nitride thin film.

4. The front-contact-based broadband indium gallium arsenide cell according to claim 1, characterized in that, The material of the positive electrode is Ti / Pt / Au.

5. The front-contact-based broadband indium gallium arsenide cell according to claim 1, wherein The material of the negative electrode is Au / Ni / Au.

6. A battery array component, characterized in that, It is formed by arranging a plurality of front-contact-based broadband indium gallium arsenide cells described in any one of claims 1-5 into a flat compact module.

7. The battery array component according to claim 6, wherein, In the flat compact module, the negative electrodes and positive electrodes of adjacent cells are connected by gold wires.

Images