Heterojunction solar cell and manufacturing method thereof
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Solution Overview
Problem
Heterojunction solar cell technology faces high equipment costs due to the expensive plate-type plasma-enhanced chemical vapor deposition (PECVD) coating equipment, making it less competitive with PERC technology in terms of comprehensive equipment investment.
Innovation Solution
A manufacturing method for heterojunction solar cells that includes forming a tunnel oxide layer and an N-type polysilicon layer on a semiconductor substrate, followed by a P-type oxygen-doped microcrystalline silicon layer, which enhances passivation and conductivity, and omits costly steps like roll coating and silicon nitride protective layers, reducing equipment investment and production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plate-type PECVD coating equipment is used for amorphous silicon or microcrystalline silicon deposition, then high conversion efficiency and good passivation are achieved, but equipment investment cost increases significantly
Solution Approach 1:
The patent changes the deposition method from plate-type PECVD to tube-type LPCVD, altering the process parameters (deposition technique, reactor type) to achieve similar passivation quality with lower equipment cost. The tube-type LPCVD equipment is less expensive while still producing high-quality amorphous silicon layers for passivation.
Solution Approach 2:
The patent uses a simpler, less expensive tube-type LPCVD equipment instead of costly plate-type PECVD equipment. The approach accepts that the equipment is less sophisticated but achieves the necessary passivation function through optimized process parameters and layer结构设计.
2Device complexity
If N-type polysilicon layer is used for back surface contact, then conductivity is maintained with low equipment investment, but passivation effect is insufficient
Solution Approach 1:
The patent merges two approaches: the low-cost N-type polysilicon layer for conductivity and the amorphous silicon layer deposited by tube-type LPCVD for passivation. By combining these layers, the patent achieves both good passivation and acceptable conductivity without requiring expensive plate-type PECVD equipment.
Solution Approach 2:
The patent creates a composite structure with multiple layers (N-type polysilicon layer, amorphous silicon layer, and optional P-type microcrystalline silicon layer) that work together to provide both passivation and conductivity functions, compensating for the limitations of using a single material system.
3Reliability
If conventional heterojunction technology is used, then high open-circuit voltage is achieved, but equipment cost remains high due to PECVD requirements
Solution Approach 1:
The patent changes the deposition equipment type from plate-type PECVD to tube-type LPCVD, maintaining the heterojunction structure's high open-circuit voltage capability while reducing equipment costs. The process parameter change enables the same functional performance with less expensive equipment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves good passivation and conductivity, improves open-circuit voltage and fill factor, and significantly lowers the total cost of heterojunction device production by reducing the need for expensive PECVD equipment, while maintaining high conversion efficiency and stability.
Implementation Method 1
The tunnel oxide passivated contact (TOPCON) technology formed by a tunnel oxide layer and an N-type polysilicon layer on a back surface of the heterojunction solar cell has a good passivation effect
Implementation Method 2
An oxygen-containing microcrystalline layer enhances an electrical potential barrier, while expanding an optical band gap
Implementation Method 3
The deposited silicon nitride protective layer prevents corrosion of the N-type polysilicon layer in the texturing solution
Implementation Method 4
the heterojunction solar cell has been increasingly popular in the photovoltaic industry and is envisioned as a future development trend for high-conversion-efficiency solar cells
Data Source
AI summary
A heterojunction solar cell and a manufacturing method thereof are provided. The manufacturing method includes the following steps: A: forming a tunnel oxide layer on a surface of a semiconductor substrate; B: forming an N-type polysilicon layer on the tunnel oxide layer; C: forming a mask layer on the N-type polysilicon layer of a first main surface of the semiconductor substrate; D: performing texturing and cleaning on a second main surface of the semiconductor substrate, and removing the mask layer; E: forming a second intrinsic amorphous silicon layer on the second main surface of the semiconductor substrate; and F: forming a P-type oxygen-doped microcrystalline silicon layer on the second intrinsic amorphous silicon layer.