CN-122028513-A - Three-terminal five-junction solar cell and preparation method thereof

CN122028513ACN 122028513 ACN122028513 ACN 122028513ACN-122028513-A

Abstract

The invention discloses a three-terminal five-junction solar cell and a preparation method thereof, belonging to the technical field of solar cells, comprising an AlGaInP sub-cell, a first tunneling junction, an InGaAs sub-cell, a second tunneling junction, a GaAs sub-cell, a third tunneling junction, a transverse conducting layer, a first gradual change buffer layer, a GaInAs sub-cell, a fourth tunneling junction, a second gradual change buffer layer, a GaInAs sub-cell and a p-type InGaAs cap layer which are arranged from top to bottom, the AlGaInP sub-cell is provided with an upper electrode, a lower electrode is arranged at the bottom of the p-type InGaAs cap layer, and the transverse conducting layer is provided with a middle electrode. When the five-junction battery adopts a three-terminal structure, the upper three-junction/lower two-junction battery can be prepared separately, so that the influence of process fluctuation on the battery is reduced, and the yield can be improved.

Inventors

GUO HONGLIANG
WAN RONGHUA
ZHANG BAO
XUE CHAO
YAO LIYONG
LIU LIRUI

Assignees

天津蓝天太阳科技有限公司

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (10)

1. The three-terminal five-junction solar cell is characterized by comprising an AlGaInP subcell, a first tunneling junction, an InGaAs subcell, a second tunneling junction, a GaAs subcell, a third tunneling junction, a transverse conducting layer, a first gradual change buffer layer, a GaInAs subcell, a fourth tunneling junction, a second gradual change buffer layer, a GaInAs subcell and a p-type InGaAs cap layer which are arranged from top to bottom, wherein an upper electrode is arranged on the AlGaInP subcell, a lower electrode is arranged at the bottom of the p-type InGaAs cap layer, and a middle electrode is arranged on the transverse conducting layer.
2. The three-terminal five-junction solar cell according to claim 1, wherein a GaAs cap layer is provided between the upper electrode and the AlGaInP subcell.
3. The three-terminal five-junction solar cell according to claim 1, wherein the electrode widths of the upper electrode and the lower electrode are each 0.01-0.5 mm.
4. The three-terminal five-junction solar cell according to claim 1, wherein the thickness of the lateral conductive layer is 300-1000 nm.
5. The three-terminal five-junction solar cell of claim 1, wherein the doping of the lateral conductive layer is n-type doping.
6. The three-terminal five-junction solar cell according to claim 1, wherein the dopant of the lateral conductive layer is Si, se or Te, and the doping concentration is 5 x 10 18 cm -3 or more.
7. The three-terminal five-junction solar cell according to claim 1, wherein the material used for the lateral conductive layer is AlGaInAs.
8. The three-terminal five-junction solar cell of claim 1, wherein the epitaxial structure of the three-terminal five-junction solar cell comprises a GaAs substrate, and a GaInP corrosion barrier layer, gaInAs subcell, fourth tunneling junction, second graded buffer layer, inGaAs subcell, and p-type InGaAs cap layer sequentially disposed on the GaAs substrate to form a lower two-junction subcell, and a first graded buffer layer, a lateral conductive layer, a third tunneling junction, gaAs subcell, a second tunneling junction, alGaAs subcell, a first tunneling junction, alGaInP subcell, and GaAs cap layer disposed on the lower two-junction subcell to form an upper three-junction subcell.
9. The three-terminal five-junction solar cell according to claim 1, wherein the electrode materials of the upper electrode, the lower electrode and the middle electrode are a mixture of one or more of gold, copper, germanium, zinc, nickel, silver or platinum.
10. The method for manufacturing a three-terminal five-junction solar cell according to any one of claims 1 to 9, comprising the steps of: Step 1, sequentially growing a GaInP corrosion barrier layer, a GaInAs sub-cell, a fourth tunneling junction, a second gradual change buffer layer, the GaInAs sub-cell and a p-type InGaAs cap layer on a GaAs substrate, electroplating, and preparing a lower electrode to obtain a component containing two lower junction sub-cells; And 2, after the component obtained in the step 1 is inverted, transferring the component to a temporary substrate for fixing, corroding the GaAs substrate and the GaInP corrosion barrier layer, continuing to grow a first gradual change buffer layer, a transverse conducting layer, a third tunneling junction, a GaAs sub-cell, a second tunneling junction, an AlGaAs sub-cell, a first tunneling junction, an AlGaInP sub-cell and a GaAs cap layer, forming an upper three-junction sub-cell, photoetching steps, step etching, preparing an upper electrode on the upper three-junction cell, preparing a middle electrode on the transverse conducting layer, step etching, covering a gate line, covering an isolation groove, corroding the GaAs cap layer around the upper electrode, reserving the GaAs cap layer at the bottom of the upper electrode, evaporating an antireflection film, and scribing to obtain the three-terminal five-junction solar cell.

Description

Three-terminal five-junction solar cell and preparation method thereof Technical Field The invention relates to the technical field of solar cells, in particular to a three-terminal five-junction solar cell and a preparation method thereof. Background A solar cell is a device that converts light energy released by the sun into electrical energy. Photons released by the sun have a large energy range from ultraviolet to infrared, and the solar cell must be multi-junction designed to reduce the overall heat loss due to the limitation of the photoelectric conversion mechanism of the solar cell. From the end of the division, the current multi-junction battery comprises a lamination (double-junction), three-junction, four-junction, five-junction, six-junction and the like, and from the electrode division, the multi-junction battery can be divided into two ends, three ends, four ends, multiple ends and the like. Compared with batteries at two ends, the three-end battery has the outstanding advantage that the constraint condition of current matching is eliminated, so that the design is more flexible, and higher efficiency is easier to obtain. In addition, the three-terminal battery has the advantages compared with the traditional two-terminal battery: One is that multi-sided output can be achieved. The output of different powers and different voltages can be realized under the same beam of light, and the requirements of different types of periods on power supplies are met. And secondly, the influence caused by spectrum change can be better resisted. The cells at both ends are sensitive to the spectrum, and the fluctuation of the spectrum can cause the change of the current limiter cells of the cells to further influence the overall output power. For the three-terminal battery, on one hand, the influence of spectrum fluctuation on the battery is weakened due to the reduction of current matching constraint, and on the other hand, the spectrum can be complemented by the form of external current injection, so that the battery can obtain stable power output. Thirdly, the luminescence coupling phenomenon can be better utilized. For example, in a GaAs/Si three-terminal battery, the luminescent coupling generated by GaAs can be directly utilized by the Si battery and is not influenced by the working state of the silicon battery. In the prior art, the five-junction solar cell mainly comprises two ends which are led out, the two ends of the cell need to consider current matching, the design freedom degree is lower, the cell continuously grows at one time, the yield is low, and the test period is long. In reality, three-terminal batteries are present in a III-V/Si laminated solar cell, and are proposed to solve the problem of mismatching of currents of the III-V cell and the Si cell. A metal electrode is employed as a lateral conductive layer in the structure of the present invention. The invention combines the three-terminal technology with the five-junction battery to form a three-terminal five-junction battery structure and provides a corresponding realization method, and the epitaxial layer is adopted as a transverse transfer layer, so that the process is greatly simplified compared with a metal conductive layer device. Disclosure of Invention The invention aims at overcoming the technical defects in the prior art and provides a three-terminal five-junction solar cell. The invention also aims to provide a preparation method of the three-terminal five-junction solar cell. The technical scheme adopted for realizing the purpose of the invention is as follows: The utility model provides a three-terminal five-junction solar cell, includes AlGaInP subcell, first tunnel junction, inGaAs subcell, second tunnel junction, gaAs subcell, third tunnel junction, horizontal conducting layer, first gradual change buffer layer, gaInAs subcell, fourth tunnel junction, second gradual change buffer layer, gaInAs subcell and p type InGaAs cap layer that top-down set up, wherein, be provided with the upper electrode on the AlGaInP subcell, the lower electrode that p type InGaAs cap layer bottom set up, be provided with the middle electrode on the horizontal conducting layer. In the above technical scheme, a GaAs cap layer is provided between the upper electrode and the AlGaInP subcell. In the above technical scheme, the electrode widths of the upper electrode and the lower electrode are 0.01-0.5 mm. In the above technical scheme, the thickness of the transverse conducting layer is 300-1000 nm. In the above technical solution, the doping of the lateral conductive layer is n-type doping. In the above technical scheme, the dopant of the transverse conducting layer is Si, se or Te, and the doping concentration is above 5×10 18cm-3. In the above technical solution, the material used for the lateral conductive layer is AlGaInAs. In the above technical scheme, the epitaxial structure of the three-terminal five-junction solar cell comprises a GaAs sub