Film silicon photovoltaic device and manufacturing method, back electrode and photovoltaic component thereof

Abstract

The invention discloses a film silicon photovoltaic device and a manufacturing method, a back electrode and a photovoltaic component thereof. The film silicon photovoltaic device has a layered structure sequentially comprising a base plate, a transparent conductive front electrode, one or a plurality of p-i-n type photovoltaic cells and a back electrode, wherein each p-i-n type photovoltaic cell consists of a p type semiconductor film, an intrinsic i type semiconductor film and an n type semiconductor film which are based on hydrogenated silicon; the back electrode contains a silver film, a nickel film and an aluminum film which are sequentially overlapped, the silver film is positioned on one side of the back electrode, which is adjacent to the p-i-n type photovoltaic cell, and the nickel film is made of nickel or a nickel alloy containing higher than 60 percent of nickel. The full metal type back electrode made of silver, nickel and aluminum has the advantages of having high reflectivity, good electrical conductivity and strong stability, being not short-circuited easily, being convenient for producing large-area photovoltaic templates in low cost, and the like.

Description

technical field [0001] The present invention relates to the field of solar photovoltaic devices, and in particular to a thin-film silicon photovoltaic device and a manufacturing method thereof, a back electrode used for the thin-film silicon photovoltaic device, and a photovoltaic module composed of a plurality of thin-film silicon photovoltaic devices. Background technique [0002] Solar energy is a renewable energy and a clean energy that does not produce any environmental pollution. Solar photovoltaic (photovoltaic) cells are one of the hot research areas in recent years, and have formed a high-profile emerging industry. Solar cells are mainly manufactured on the basis of semiconductor materials, and their working principle is to use photoelectric materials to absorb light energy and generate photoelectric conversion reactions of photoelectrons. Different materials can be used for solar cells, including crystalline silicon, III-V compounds such as gallium arsenide, cryst...

AI Technical Summary

Problems solved by technology

[0006] However, there are serious problems with the combination of Zn0 / Ag

First, when the silicon layer of a thin-film silicon cell is thin, a sufficiently thick silver film required for low resistance can lead to significant shunts in many areas of the cell, reducing the energy conversion rate and reducing the efficiency of the photovoltaic module. Low yield

Shunt shorting tends to get worse over time and is especially problematic in the production of large area stencils

Second, the use of a thicker silver film as the back electrode significantly reduces the stability of the photovoltaic template, because silver atoms are activated by temperature under the influence of an electric field to migrate, allowing silver to diffuse into the silicon film along structural defects

Third, the instability of the silver film when exposed to moisture-containing air causes its light reflectance to decrease significantly after several months or more, which leads to the loss of power generation capacity and life of the photovoltaic template

Fourth, since silver is a precious metal, the use of thicker silver films results in higher production costs

This method can obtain uniform and reproducible large-area ZnO:Al thin films by using ceramic targets, but its disadvantages are: high equipment cost, complex target fabrication, low deposition rate (i.e., low throughput), and the substrate should be Heating to a higher temperature (for example, between 100°C and 200°C) makes the magnetron sputtering equipment capable of high-speed operation and its operation very complicated

However, especially during heat treatment at moderate temperatures (such as 130°C-200°C), the silver and aluminum films are easily mixed with each other due to diffusion.

Therefore, the light reflectance of the silver film tends to be reduced

Furthermore, as mentioned above, the deposition of ZnO is a very difficult low-throughput process

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