Preparation method of P-type heterojunction full-back electrode contact crystalline silicon photovoltaic cell

Abstract

The invention relates to a preparation method of a P-type heterojunction full-back electrode contact crystalline silicon photovoltaic cell, which comprises the steps of performing double-sided texturing to form a textured structure; performing double-sided oxidation and intrinsic polycrystalline silicon, and then performing phosphorus diffusion to form a tunneling oxidation passivation layer; forming a mask layer on the back surface by using a high-temperature oxidation process; carrying out laser film opening and cleaning on the back surface, and removing intrinsic polycrystalline silicon onthe front surface by utilizing an alkali polishing process; performing boron slurry printing on the back surface, and drying to form a P+ layer; forming a P+ layer on the front surface by adopting boron source doping; removing a BSG mask layer and a PSG mask layer by using HF; removing the redundant polycrystalline silicon layer in an alkali polishing manner; forming a passivation layer from double-sided aluminum oxide, front silicon oxynitride and back silicon nitride; carrying out silk-screen printing to form P+finger and N+finger; and conducting a low-temperature sintering process to complete manufacturing of the cell. According to the invention, the structure of an IBC cell is introduced on the basis of the existing PERC technology, and meanwhile, the structure of the intrinsic amorphous silicon is introduced, so that VOC and ISC can be effectively improved, and the efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a method for preparing a p-type heterojunction full-back electrode-contact crystalline silicon photovoltaic cell. Background technique [0002] The IBC (Interdigitated back contact) battery appeared in the 1970s and was the earliest researched back-junction battery. It was mainly used in concentrating systems at first. The battery uses an n-type substrate material, and the front and rear surfaces are covered with a layer of thermal oxide film to reduce surface recombination. Using photolithography technology, local diffusion of phosphorus and boron is carried out on the back of the battery respectively, forming a P region and an N region arranged in a finger-like intersecting manner, and a P+ region and an N+ region located above it. The P+ and N+ regions formed by re-expansion can effectively eliminate the voltage saturation effect under high concentration conditions. In a...

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Problems solved by technology

Its technology has the following disadvantages: 1. The battery structure is relatively simple. If the efficiency needs to be further improved, the existing equipment does not have much space; 2. LID light-induced attenuation is still serious

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