Defect-engineered interface layer enhanced gaas / pedot:pss hybrid solar cell and preparation method

Abstract

The application belongs to the technical field of solar cells, and discloses a GaAs / PEDOT:PSS hybrid solar cell with a defect-engineered interface layer and a preparation method. The solar cell comprises, from bottom to top, a back electrode, a substrate, a vanadium pentoxide interface layer with oxygen vacancies, a PEDOT:PSS / Ag nanowire composite layer, and a top electrode. The oxygen vacancy concentration in the vanadium pentoxide interface layer with oxygen vacancies is 0.45% to 7.78%, and the thickness is 8 to 17 nm. The composite layer is obtained by compounding PEDOT:PSS and Ag nanowires. The application also discloses a preparation method of the solar cell. The interface layer of the application blocks the corrosion of acidic components, suppresses the surface load of electrons, and assists in hole transport. The application effectively solves the efficiency bottleneck problem caused by acidic corrosion and interface recombination, improves the performance of the solar cell, and makes the solar cell have high conversion efficiency.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a GaAs / PEDOT:PSS hybrid solar cell based on a defect-engineered interface layer and silver nanowire conductivity enhancement, and its preparation method. Background Technology

[0002] Gallium arsenide-based solar cells are widely used in the field of new energy technology due to their high conversion efficiency, strong radiation resistance, and high specific power. However, the raw materials for III-V solar cells are relatively scarce compared to silicon-based cells. At the same time, their epitaxial technology often requires large-scale equipment such as MBE and MOCVD, which greatly increases the manufacturing cost due to the complexity of the process. All of these factors have prevented its expansion in the civilian field.

[0003] To address this, researchers have attempted to form simple heterojunction solar cells with GaAs substrates using low-dimensional materials (graphene, MXene, CNTs, etc.) and organic hole transport materials (P3HT, PEDOT:PSS, polyaniline, etc.), providing a solution to overcome the aforementioned bottlenecks. The former can replace noble metal electrodes to reduce optical losses, while the latter, with its low-temperature solution processability (<150℃) and flexible compatibility, significantly improves the cost-effectiveness and mechanical robustness of the devices. Among these, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is considered one of the most ideal candidates for organic hole transport layers due to its high conductivity, high visible light transmittance, and good energy level matching with the valence band top of GaAs. However, the efficiency of GaAs / PEDOT:PSS organic-inorganic hybrid solar cells is still far lower than that of current mainstream silicon-based solar cells, with the highest efficiency to date being only 15.08%. This is mainly due to a serious interface problem between the two materials: on the one hand, the Fermi level pinning effect on the GaAs surface caused by the interface state is mismatched with the charge extraction capability of PEDOT:PSS, resulting in an interface recombination rate that is much higher than the ideal value, which affects the fill factor of the device; on the other hand, the strong acidity of PEDOT:PSS (pH < 2) will induce oxidation on the GaAs surface (forming As-O / Ga-O defect states), which will cause a surge in the interface recombination current density, resulting in battery efficiency and stability that are much lower than theoretically expected.

[0004] To address the failure problem at the PEDOT:PSS / GaAs interface, researchers have attempted strategies such as passivation, in-situ chemical neutralization, and nanoparticle doping, but all have significant drawbacks. For example, depositing InGaP or InAsP as intermediate layers using processes such as MBE and ALD, or performing chemical passivation using nitrides and sulfides such as hydrazine and ammonium sulfide, can effectively reduce the surface defect states of GaAs substrates to 10-10. 2cm / s, but the high vacuum preparation conditions and the complexity of GaAs surface pretreatment process severely restrict large-scale application. The reagents used in the latter are mostly toxic and harmful, posing a high risk. While neutralizing acidic treatment methods such as NH4OH and NaOH can alleviate corrosion and improve hygroscopicity, they come at the cost of sacrificing conductivity and film uniformity.

[0005] Solving the PEDOT:PSS / GaAs interface failure problem and improving the performance of PEDOT:PSS / GaAs hybrid solar cells is one of the problems that needs to be solved. Summary of the Invention

[0006] To overcome the shortcomings and deficiencies of existing technologies, the present invention aims to provide a GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement and its fabrication method. The present invention utilizes thermal evaporation to enhance V2O... 5-x Introducing the GaAs and PEDOT:PSS interface, a performance breakthrough is achieved through a dual synergistic mechanism: (1) Interface passivation effect: dense V2O 5-x The layer can effectively isolate the acidic components of PSS from eroding GaAs. On the other hand, the field effect passivation caused by the high work function can suppress the surface load of electrons; (2) Assist hole transport: By controlling the oxygen vacancy concentration and optimizing the film thickness through the annealing atmosphere, defect-assisted tunneling can be induced and the interface band bending can be enhanced, thereby synergistically reducing the hole injection barrier. In order to further optimize the device performance, this invention introduces low-concentration silver nanowires (AgNWs) as a conductivity enhancer in the PEDOT:PSS layer. Its three-dimensional conductive network effectively alleviates the lateral transport bottleneck of PEDOT:PSS. The incorporation of Ag NWs increases the in-plane conductivity of the composite hole transport layer from 797 S / cm of pure PEDOT:PSS to 950 S / cm, thereby reducing the series resistance (Rs) from 4.21 Ω·cm² to 2.27 Ω·cm². This enables the device to achieve an efficiency of 16.46% under AM1.5G illumination. This invention effectively solves the efficiency bottleneck problem caused by acid corrosion and interface recombination.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement includes a back electrode, a substrate, a vanadium pentoxide interface layer with oxygen vacancies, a PEDOT:PSS / Ag nanowire composite layer, and a top electrode stacked sequentially from bottom to top.

[0009] The oxygen vacancy concentration in the vanadium pentoxide interface layer with oxygen vacancies is 0.45%-7.78%, preferably 1-6%, and more preferably 2.5-4.5%.

[0010] The vanadium pentoxide interface layer with oxygen vacancies is V2O. 5-x Interface layer, V2O 5-x x ranges from 0.0225 to 0.3891.

[0011] The PEDOT:PSS / Ag nanowire composite layer is obtained by combining PEDOT:PSS with Ag nanowires;

[0012] The composite layer was prepared by the following method: PEDOT:PSS, DMSO, and a surfactant were mixed to obtain a mixture; the mixture was then mixed with a silver nanowire solution to obtain a silver nanowire-containing solution; a film was formed on the interface layer to obtain the PEDOT:PSS / Ag nanowire composite layer. The film was then annealed. The annealing conditions were: temperature 120-130℃, time 15-20 min.

[0013] The concentration of DMSO in the mixture is 3-7 wt%, and the concentration of surfactant is 0.1-0.6 wt%. At this concentration, the basic conductivity of the PEDOT:PSS film is high, and the residue after annealing has minimal impact on device performance.

[0014] The concentration of Ag NWs (silver nanowires) in a mixed solution containing silver nanowires is 0.6-1.8 mg / mL, preferably 1-1.4 mg / mL. The conductivity gain at this concentration can offset the negative effects of aggregation and reflection.

[0015] The surfactant is FS-300 or Triton X-100.

[0016] When the surfactant is FS-300, the surfactant concentration is 0.1-0.3wt%; when the surfactant is Triton X-100, the surfactant concentration is 0.4-0.6wt%.

[0017] The thickness of the vanadium pentoxide interface layer with oxygen vacancies is 8~17nm, preferably 10~14nm.

[0018] The thickness of the PEDOT:PSS / Ag nanowire composite layer is 35~45nm.

[0019] The thickness of the back electrode is 60~140nm.

[0020] The top electrode is a grid electrode. The material of the top electrode is Ag.

[0021] The material of the back electrode is Au.

[0022] A method for fabricating a GaAs / PEDOT:PSS hybrid solar cell enhanced with a defect-engineered interface layer includes the following steps:

[0023] (1) A back electrode is deposited on the back side of a clean GaAs substrate and then annealed.

[0024] (2) A thin film of V2O5 is deposited on the front side of the GaAs substrate by thermal evaporation, followed by annealing to obtain V2O. 5-x Interface layer;

[0025] (3) PEDOT:PSS, DMSO and surfactant are mixed to obtain a mixture; the mixture is mixed with silver nanowire solution to obtain a mixed solution containing silver nanowires; a film is formed on the interface layer to obtain a PEDOT:PSS / Ag nanowire composite layer;

[0026] (4) A gate electrode was fabricated on the PEDOT:PSS / Ag nanowire composite layer by means of a mask.

[0027] The clean GaAs substrate mentioned in step (1) refers to ultrasonically cleaning the GaAs substrate with HCl, acetone and ethanol in sequence, and then drying it.

[0028] The annealing conditions described in step (1) are: annealing time of 25~35 s and annealing temperature of 300~360 ℃. Under these conditions, the back electrode Au can form a good ohmic contact with the substrate, while preventing Au atoms from diffusing into the substrate to form deep-level impurities.

[0029] In step (2), thermal evaporation refers to the process of heating vanadium pentoxide under high vacuum conditions to melt and vaporize it. The vaporized vanadium pentoxide then cools and forms a nucleus and film when it comes into contact with the substrate.

[0030] The vacuum degree of thermal evaporation in step (2) is less than 9.9 × 10⁻⁶. -4 The evaporation rate is 0.1–0.3 Å / s. Under these conditions, V₂O 5-x The thin film can be uniformly attached to the substrate surface.

[0031] The annealing conditions described in step (2) are: 250~400℃ (preferably 280~350℃) for 15~30 min in an air atmosphere.

[0032] In step (2), the thermally evaporated film is annealed in an air atmosphere, V2O 5-x The thin film forms an orthorhombic crystalline phase, for example, the characteristic diffraction peaks at 15.3 ̊, 20.3 ̊, 31.0 ̊, 32.4° and 47.3 ̊ are located at the annealing temperature of 390°.

[0033] V2O in step (2) 5-x The oxygen vacancy concentration in the interface layer ranges from 0.45% to 7.78%, while V2O...5-x The value of x also changed from 0.0225 to 0.3891, and the device performance degraded after the oxygen vacancy rate exceeded 7.78%.

[0034] In step (3), the concentration of DMSO in the mixture is 3-7 wt%, and the concentration of surfactant is 0.1-0.6 wt%. At this concentration, the basic conductivity of the PEDOT:PSS film is relatively high, and the residue after annealing has the least impact on the device performance.

[0035] The concentration of Ag NWs (silver nanowires) in a mixed solution containing silver nanowires is 0.6-1.8 mg / mL, preferably 1-1.4 mg / mL. The conductivity gain at this concentration can offset the negative effects of aggregation and reflection.

[0036] The surfactant is FS-300 or Triton X-100.

[0037] When the surfactant is FS-300, the surfactant concentration is 0.1-0.3wt%; when the surfactant is Triton X-100, the surfactant concentration is 0.4-0.6wt%.

[0038] The silver nanowires have a diameter of 50-60 nm and a length of >10 μm.

[0039] In step (3), the film is annealed after formation. The annealing conditions are: temperature 120-130℃, time 15-20min. Under these conditions, moisture and residues can be effectively removed, grain rearrangement can be promoted, and the adhesion of the film can be effectively enhanced.

[0040] The film formation mentioned in step (3) refers to spin coating; the spin coating speed and time are 4500-6500 rpm and 90-120s.

[0041] Compared with the prior art, the advantages of the present invention are as follows:

[0042] (1) Simple process: It avoids the use of large-scale equipment such as MBE and MOCVD, reducing preparation cost and process complexity;

[0043] (2) It avoids the use of sulfur and ammonia compounds, effectively reducing the risk of poisoning;

[0044] (3) Synergistic effect, V2O 5-x The interface layer can act as both a physical barrier and an aid in carrier transport.

[0045] (4) The present invention significantly improves the photoelectric conversion efficiency of solar cells. Attached Figure Description

[0046] Figure 1This is a schematic diagram of the structure of the solar cell of the present invention. 1-back electrode, 2-substrate, 3-vanadium pentoxide interface layer with oxygen vacancies, 4-PEDOT:PSS / Ag nanowire composite layer, 5-top electrode (i.e., grid electrode).

[0047] Figure 2 The JV curves are for the solar cells of Examples 1-4 and Comparative Examples 1-2;

[0048] Figure 3 External quantum efficiency curves for solar cell devices doped with 1.2 mg / ml Ag NWs and undoped Ag NWs;

[0049] Figure 4 The conductivity and sheet resistance of PEDOT:PSS films with different silver nanowire concentrations were measured using the four-probe method.

[0050] Figure 5 For comparison of the series resistance of Comparative Example 2 and Example 4. Detailed Implementation

[0051] The present invention will be described in further detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0052] The defect-engineered interface layer-enhanced GaAs / PEDOT:PSS hybrid solar cell of the present invention is shown in the schematic diagram below. Figure 1 As shown, the structure includes, from bottom to top, a back electrode 1, a substrate 2, a vanadium pentoxide interface layer 3 with oxygen vacancies, a PEDOT:PSS / Ag nanowire composite layer 4, and a top electrode 5.

[0053] The oxygen vacancy concentration in the vanadium pentoxide interface layer with oxygen vacancies is 0.45%-7.78%, preferably 1-6%, and more preferably 2.5-4.5%.

[0054] The vanadium pentoxide interface layer with oxygen vacancies is V2O. 5-x Interface layer, V2O 5-x x ranges from 0.0225 to 0.3891.

[0055] The PEDOT:PSS / Ag nanowire composite layer is obtained by combining PEDOT:PSS with Ag nanowires.

[0056] The substrate is a GaAs substrate or a GaAs substrate with an InGaP back field layer.

[0057] The thickness of the vanadium pentoxide interface layer with oxygen vacancies is 8~17nm, preferably 10~14nm.

[0058] The thickness of the PEDOT:PSS / Ag nanowire composite layer is 35~45nm.

[0059] The top electrode is a grid electrode.

[0060] When the substrate is a GaAs substrate with an InGaP back field layer, the back electrode is disposed on the InGaP back field layer.

[0061] Example 1: No V2O 5-x Thin film annealing

[0062] (1) The GaAs substrate was ultrasonically treated with 10wt% hydrochloric acid, acetone and ethanol for 5 minutes each, cleaned and dried with nitrogen gun; Au back electrode was deposited on the back side of the clean GaAs substrate and annealed at 330℃ for 30s; the thickness of Au was 80nm.

[0063] (2) Place V2O5 powder in a tungsten boat, ensuring it covers the bottom of the boat, and place it in the evaporation chamber. Use a mechanical pump and a molecular pump sequentially to reduce the vacuum level in the chamber to 6.8 × 10⁻⁶. -4 Pa was used to adjust the thermal evaporation current intensity to achieve a deposition rate of 0.15 Å / s on the front side of the substrate. Evaporation was stopped when the deposition thickness reached 12 nm. At this point, V... 5+ The proportion is 61.09% (when V2O5 thin film deposition is carried out by thermal evaporation, V2O5 will decompose simultaneously under high vacuum conditions, causing some pentavalent vanadium to be converted into tetravalent vanadium, thus generating oxygen vacancies in the film. The proportion here refers to the atomic ratio of pentavalent vanadium in the film among all vanadium elements. Assuming that the proportion of pentavalent vanadium is m and the proportion of tetravalent vanadium is n, then m+n=1 should be satisfied, and both m and n are greater than or equal to zero and less than or equal to 1. At this time, the concentration of oxygen vacancies can be expressed as (5-5m-4n) / 5*100%).

[0064] (3) Take 1 ml of PEDOT:PSS (Clevios PH1000) solution, add 5 wt% DMSO and 0.15 wt% Zonyl FS-300 surfactant to it, stir at 1000 rpm for 3 h to obtain PEDOT:PSS mixed solution (where the mass percentage refers to the concentration of DMSO in PEDOT:PSS mixed solution is 5 wt% and the concentration of surfactant in PEDOT:PSS mixed solution is 0.15 wt%); then place it in a refrigerator at 4-8℃ for later use;

[0065] (4) Using a spin coater at a speed of 6000 rpm and a spin coating time of 90 s, in V2O 5-xA PEDOT:PSS mixture was spin-coated onto the layer, and then annealed at 126°C for 16 minutes on a hot plate to obtain the PEDOT:PSS / composite layer; the thickness of the composite layer was 40±3 nm.

[0066] (5) An Ag gate electrode was deposited on the PEDOT:PSS composite layer using a hard mask to obtain the target device. The thickness of the gate electrode was 120 nm.

[0067] In this embodiment, the grid electrode has one thick grid line, 16 thin grid lines, and one contact. After the silver grid is deposited, the light-shielding area is reduced to 1 cm. 2 The effective light-absorbing area on the substrate is 0.9~0.97 cm². 2 .

[0068] The short-circuit current density of the device fabricated in this embodiment is 14.20 mA / cm². 2 The open-circuit voltage is 622.57mV and the fill factor is 56.18%.

[0069] Example 2

[0070] The difference between this embodiment and Embodiment 1 is that in step (2), after the thin film is deposited, it is annealed for 20 minutes in an air atmosphere at 300°C. At this time, V 5+ The concentration was 83.7% (corresponding to an oxygen vacancy concentration of 3.26%), and the other steps and parameters were the same as in Example 1.

[0071] Example 3

[0072] The difference between this embodiment and embodiment 2 is that in step (2), V2O 5-x The thickness of the thin film deposition was 16 nm, and the other steps and parameters were the same as in Example 2.

[0073] Example 4

[0074] The difference between this embodiment and Embodiment 2 is as follows: Step (1) uses a GaAs substrate with an InGaP back field layer, and the back electrode is fabricated on the back field layer; Step (3) adds an additional 20.5 μl of Ag NWs concentrate with a concentration of 60 mg / ml to the PEDOT:PSS mixture, so that its concentration in the final mixture is 1.2 mg / ml. Other steps and parameters are the same as in Embodiment 2.

[0075] Comparative Example 1

[0076] The difference between this comparative example and Example 1 is that this scheme does not involve V2O. 5-x The other steps and parameters for thin film deposition are the same as in Example 1.

[0077] Comparative Example 2

[0078] The difference between this comparative example and Example 4 is that this method does not add Ag NWs, while the other steps and parameters are the same as in Example 4.

[0079] Comparative Example 3

[0080] The difference between this comparative example and Example 2 is that the annealing environment is changed to vacuum conditions, and the annealing temperature is 300°C. At this temperature, V... 5+ The percentage was 36.38%.

[0081] Performance testing

[0082] The electrical performance of the solar cells obtained in Examples 1-4 and Comparative Examples 1 and 2 was tested, and the results are shown in Table 1.

[0083] Table 1 shows the electrical performance of the solar cells obtained in Examples 1-4 and Comparative Examples 1 and 2.

[0084]

[0085] As can be seen from Table 1:

[0086] Comparing Example 1 with Comparative Example 1, it can be found that all aspects of the battery performance have been improved to varying degrees, indicating that even with V2O 5-x Even without annealing, it already optimizes device performance. Its high work function can form a field-effect passivation effect on the GaAs surface, while also acting as a physical barrier to prevent acid corrosion and surface oxidation under atmospheric conditions.

[0087] Compared to Example 2, V2O is improved. 5-x When the film thickness reaches 16 nm as in Example 3, the device performance begins to decline. This is because an excessively thick film will cause the series resistance of the system to increase, and the carriers will encounter more oxygen vacancy defects during transport in the film, resulting in recombination, which in turn leads to a decrease in the fill factor and open-circuit voltage.

[0088] Compared to Example 1, Example 2 involves annealing in an oxygen-containing atmosphere to reduce V 5+ With the concentration increasing to 83.70%, the device performance in Example 2 showed a more significant improvement. This is because appropriate oxygen vacancy repair can reduce the probability of nonradiative recombination of charge carriers under the influence of oxygen defects while assisting hole transport. In Comparative Example 3, annealing in a vacuum environment resulted in V... 5+ When the concentration drops to 36.38%, the oxygen vacancy concentration in the thin film increases significantly. The oxygen vacancy concentration used to assist in hole transport becomes supersaturated. The large number of oxygen defects greatly increases the probability of nonradiative recombination of charge carriers, resulting in a significant deterioration in device performance.

[0089] Furthermore, by comparing Example 4 with Comparative Example 2 using a GaAs substrate with an InGaP back field layer structure, it can be found that the short-circuit current density and fill factor of the device are significantly improved after adding Ag NWs. Ag NWs can bridge the PEDOT conductive core in the PSS insulating shell after partially dissolving it in DMSO, thereby reducing the current loss of the device and achieving a conversion efficiency of 16.46%, which is also a new record for GaAs / PEDOT:PSS heterojunction cells.

[0090] Figure 2 The JV curves are for the solar cells of Examples 1-4 and Comparative Examples 1-2.

[0091] Figure 3 External quantum efficiency curves for solar cell devices doped with 1.2 mg / ml Ag NWs (Example 4) and undoped Ag NWs (Comparative Example 2).

[0092] Figure 4 The conductivity and sheet resistance of PEDOT:PSS films with different silver nanowire concentrations were measured using the four-probe method. Following step (3) in Example 4, the concentrations of silver nanowires in the mixed solution were 0, 0.6, and 1.2 mg / ml. Then, films were formed according to step (4), and the conductivity and sheet resistance of the films were measured.

[0093] Figure 5 For comparison of the series resistance of Comparative Example 2 and Example 4.

Claims

1. A GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement, characterized in that: It includes a back electrode, a substrate, a vanadium pentoxide interface layer with oxygen vacancies, a PEDOT:PSS / Ag nanowire composite layer, and a top electrode, which are stacked sequentially from bottom to top. The oxygen vacancy concentration in the vanadium pentoxide interface layer with oxygen vacancies is 0.45%-7.78%; The PEDOT:PSS / Ag nanowire composite layer is obtained by combining PEDOT:PSS with Ag nanowires; The substrate is a GaAs substrate or a GaAs substrate with an InGaP back field layer.

2. The GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 1, characterized in that: The oxygen vacancy concentration in the vanadium pentoxide interface layer with oxygen vacancies is 1-6%; The thickness of the vanadium pentoxide interface layer with oxygen vacancies is 8~17 nm; The PEDOT:PSS / Ag nanowire composite layer is prepared by the following method: PEDOT:PSS, DMSO and surfactant are mixed to obtain a mixed solution; the mixed solution is mixed with a silver nanowire solution to obtain a mixed solution containing silver nanowires; a film is formed on a vanadium pentoxide interface layer with oxygen vacancies to obtain the PEDOT:PSS / Ag nanowire composite layer.

3. The GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 2, characterized in that: The oxygen vacancy concentration in the vanadium pentoxide interface layer with oxygen vacancies is 2.5% to 4.5%. The thickness of the vanadium pentoxide interface layer with oxygen vacancies is 10~14 nm; In the preparation of the PEDOT:PSS / Ag nanowire composite layer, the concentration of DMSO in the mixture is 3-7 wt%, and the concentration of surfactant is 0.1-0.6 wt%. The concentration of silver nanowires in the mixed solution containing silver nanowires is 0.6~1.8 mg / mL.

4. The GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 3, characterized in that: The concentration of the silver nanowires in the mixed solution containing silver nanowires is 1~1.4 mg / mL; The surfactant is FS-300 or Triton X-100.

5. The GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 4, characterized in that: When the surfactant is FS-300, the surfactant concentration is 0.1-0.3 wt%; when the surfactant is Triton X-100, the surfactant concentration is 0.4-0.6 wt%. In the preparation of PEDOT:PSS / Ag nanowire composite layers, annealing is performed after film formation. The annealing conditions are: temperature 120-130℃, time 15-20min.

6. The GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 1, characterized in that: The thickness of the PEDOT:PSS / Ag nanowire composite layer is 35~45nm; The thickness of the back electrode is 60~140nm; The top electrode is a grid-shaped electrode; The material of the top electrode is Ag; The material of the back electrode is Au.

7. The method for fabricating a GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to any one of claims 1 to 6, characterized in that: Includes the following steps: (1) A back electrode is deposited on the back side of a clean substrate and then annealed. The substrate is a GaAs substrate or a GaAs substrate with an InGaP back field layer. When the substrate is a GaAs substrate with an InGaP back field layer, the back electrode is disposed on the InGaP back field layer. (2) A thin film of V2O5 is deposited on the front side of the substrate by thermal evaporation, followed by annealing to obtain V2O. 5-x Interface layer; the annealing process is an air-atmosphere annealing process; the annealing process reduces V2O 5-x The oxygen vacancy concentration in the interface layer ranges from 0.45% to 7.78%. (3) PEDOT:PSS, DMSO and surfactant are mixed to obtain a mixture; the mixture is mixed with silver nanowire solution to obtain a mixed solution containing silver nanowires; a film is formed on the interface layer to obtain a PEDOT:PSS / Ag nanowire composite layer; (4) A gate electrode was fabricated on the PEDOT:PSS / Ag nanowire composite layer by means of a mask.

8. The method for fabricating a GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 7, characterized in that: The annealing conditions described in step (2) are as follows: annealing at 250~400℃ in an air atmosphere for 15~30 minutes; The V2O 5-x The interface layer is a vanadium pentoxide interface layer with oxygen vacancies, and the oxygen vacancy concentration is 1~6%; The V2O 5-x The thickness of the interface layer is 8~17nm; The vacuum degree of thermal evaporation in step (2) is less than 9.9 × 10⁻⁶. -4 Pa, with an evaporation rate of 0.1–0.3 Å / s; In step (3), the concentration of DMSO in the mixture is 3-7 wt%, and the concentration of surfactant is 0.1-0.6 wt%. In step (3), the concentration of silver nanowires in the mixed solution containing silver nanowires is 0.6-1.8 mg / mL; In step (3), the film is annealed after formation. The annealing conditions are: temperature 120-130℃, time 15-20min.

9. The method for fabricating a GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 8, characterized in that: V2O 5-x The interface layer is a vanadium pentoxide interface layer with oxygen vacancies, and the oxygen vacancy concentration is 2.5~4.5%; The V2O 5-x The thickness of the interface layer is 10~14nm; The concentration of the silver nanowires in the mixed solution containing silver nanowires is 1~1.4 mg / mL; The surfactant is FS-300 or Triton X-100; when the surfactant is FS-300, the concentration of the surfactant is 0.1-0.3 wt%; when the surfactant is Triton X-100, the concentration of the surfactant is 0.4-0.6 wt%. The silver nanowires have a diameter of 50-60 nm and a length of >10 μm.

10. The method for fabricating a GaAs / PEDOT:PSS hybrid solar cell with defect-engineered interface layer enhancement according to claim 8, characterized in that: The clean substrate mentioned in step (1) refers to ultrasonically cleaning the substrate sequentially with HCl, acetone, and ethanol, and then drying it. The annealing conditions described in step (1) are: annealing time of 25~35 s and annealing temperature of 300~360 ℃; The film formation mentioned in step (3) refers to spin coating; the spin coating speed and time are 4500-6500 rpm and 90-120s.

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