Local doping method for solar cells

Abstract

Disclosed in the present invention is a solar cell local-area doping method. The method comprises the steps: (a) molecular films with hydrophilic groups and / or hydrophobic groups are formed on the surface of a substrate; (b) doping sources are provided on the surface of the substrate said in the step (a), and the doping sources are distributed on the patterns formed by the molecular films; and (c) the thermal diffusion is conducted to the obtained substrate in the step (b), and therefore the substrate of the local-area doping solar cell is formed. According to the method in the present invention, the local-area doping structures with different patterns and sizes can be obtained, and the method is particularly suitable for building local-area emitter junctions and high-low surface fields of the solar cell.

Description

technical field

[0001] The invention relates to a local doping method of a solar cell, belonging to the technical field of solar cells. Background technique

[0002] Diffusion doping technology is to deposit and coat gas phase and liquid phase substances containing doping elements (such as phosphorus, boron, etc.) on the surface of the substrate. Diffuse to the substrate to form N-type or P-type doping. Since the doping source is applied to the entire surface of the substrate, this technology can only form uniform doping on the entire surface, and cannot realize the local emitter junction and high and low junction surface fields of solar cells. At present, the heavy doping of the local contact area is mainly formed on the back surface of the silicon wafer by mask technology, and then diffused at high temperature; or the non-doped area is etched by etching technology. These processes greatly increase process steps and costs. Contents of the invention

[0003] The technic...

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