Photovoltaic cell with three layers of antireflective films in composite structures and composite coating method thereof

Abstract

The invention discloses a photovoltaic cell with three layers of antireflective films in composite structures and a composite coating method thereof. Three layers of silicon nitride antireflective films in composites structures are coated on the surface of a silicon chip of the photovoltaic cell from inside to outside, thicknesses and refractive indexes are 10nm, 2.3; 22nm, 2.16; and 50nm, 2.0 respectively. Through refraction synthesis of composite film layers, the absorption bandwidth of the silicon chip to sunshine of each frequency spectrum band is expanded, reflection is reduced maximally to improve the photoelectric conversion efficiency of the photovoltaic cell, the defects that the antireflection spectral bandwidth is narrow and the photoelectric conversion efficiency is difficult to improve in the prior art are overcome, the antireflection spectral bandwidth is expanded and the photoelectric conversion efficiency is improved through the three layers of the silicon nitride antireflective films in composites structures.

Description

technical field [0001] The present invention relates to a solar photovoltaic cell, specifically refers to a photovoltaic cell of a three-layer composite structure antireflection film deposited on the surface of a solar photovoltaic cell and a silicon nitride antireflection film for reducing surface reflection and improving photoelectric conversion efficiency and its composite coating method. Background technique [0002] In order to reduce the surface reflection and improve the photoelectric conversion efficiency of the solar photovoltaic cell, it is necessary to deposit a silicon nitride anti-reflection film on the surface of the silicon wafer. The prior art adopts plasma-enhanced chemical vapor deposition method PECVD to combine nitrogen and silicon to form a silicon nitride film for reducing reflection on the surface of the silicon wafer; the silicon nitride anti-reflection film of the prior art is a single-layer film, Due to the narrow bandwidth of the anti-reflection s...

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Problems solved by technology

The prior art adopts plasma-enhanced chemical vapor deposition method PECVD to combine nitrogen and silicon to form a silicon nitride film for reducing reflection on the surface of the silicon wafer; the silicon nitride anti-reflection film of the prior art is a single-layer film, Due to the narrow bandwidth of the anti-reflection spectrum of the single-layer film, it only has an anti-reflection effect on certain spectrum bands of sunlight radiation, while more than 35% of the sunlight in other spectrum bands is reflected by the surface of the silicon wafer of the battery, resulting in solar photovoltaic cells. It is difficult to improve the photoelectric conversion efficiency because it cannot fully absorb sunlight radiation energy in other bands; therefore, the existing technology has the problems and shortcomings of narrow anti-reflection spectrum bandwidth and difficult improvement of photoelectric conversion efficiency

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