N type doped silicon film, preparation method of N type doped silicon film and solar cell comprising N type doped silicon film

Abstract

The invention provides an N type doped silicon film, a preparation method of the N type doped silicon film and a solar cell comprising the N type doped silicon film. The preparation method comprises the following step that: deposition is carried out on a solar cell semi-finished product positioned in a reaction chamber by utilizing a plasma enhanced chemical vapour deposition process, such that the N type doped silicon film is formed; reaction gas in the plasma enhanced chemical vapour deposition process comprises silicon source gas, hydrogen and doped gas, wherein the flow ratio of hydrogen to silicon source gas is 80:1 to 150:1; when the plasma enhanced chemical vapour deposition process is implemented, the surface temperature of the solar cell semi-finished product is 50-70 DEG C; the discharge power density of the plasma enhanced chemical vapour deposition process is 0.8-1.5 W / cm<2>; the reaction pressure is 500-750 Pa; the grain size of the formed N type doped silicon film is less than 5 nm; the bandwidth is greater than 1.9 eV; and the activation energy is less than 0.1 eV. The conversion efficiency of the solar cell can be increased.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to an N-type doped silicon thin film, a preparation method thereof and a solar cell comprising the same. Background technique [0002] Silicon-based solar cells include monocrystalline silicon heterojunction solar cells and silicon thin-film solar cells, wherein the N-type silicon layer is an essential structure in the above-mentioned types of silicon-based solar cells. In the prior art, amorphous silicon thin films are usually used as the N-type silicon layer in single-crystal silicon heterojunction solar cells and silicon thin-film solar cells. However, the energy band width of amorphous silicon thin films is about 1.8eV, and the activation of N-type doping The energy is about 0.4eV. The above-mentioned small energy band width and large activation energy are not only not conducive to the establishment of the built-in electric field of the solar cell and the collection of photo...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a kind of N-type doped silicon thin film, its preparation method and the solar cell comprising it, to solve the problem of solar cells caused by N-type doped silicon thin film prepared by amorphous silicon thin film in the prior art. The problem of lower conversion efficiency

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