Deep hole staggered back contact solar battery structure and manufacturing method thereof

Abstract

The invention relates to a photovoltaic device for converting optical energy into electrical energy, and specifically relates to a deep hole staggered back contact solar battery structure and a manufacturing method of the photovoltaic device. By adopting a laser ablation method, deep holes with same depth are respectively formed on the upper surfaces of a P+ type diffusion zone and a N+ type diffusion zone which are formed on the back surface in a staggered manner, wherein the deep holes are not deep enough to reach a doping zone on the front surface of a silicon substrate. The deep holes respectively have same doping concentration and doping depth with the local diffusion zone. According to the invention, by the method of manufacturing the deep holes on a base electrode and an emitting electrode, the problems of failure in effective collection of some short life current carriers and high series resistance cased by long transmission distance of the current carriers in the conventional staggered back electrode scheme are solved. The deep hole structure greatly shortens the diffusion distance of the photon-generated carriers, thus, more photon-generated carriers are collected and the recombination loss of the photon-generated carriers is reduced, the series resistance of batteries is reduced, and the conversion efficiency of the solar battery is further improved.

Description

technical field [0001] The invention relates to a photovoltaic device for converting light energy into electric energy, in particular to a deep-hole staggered back-contact solar cell structure and a manufacturing method thereof. Background technique [0002] At present, one of the most typical solar cell manufacturing methods is to adopt a double-sided electrode scheme, that is, a solar cell manufacturing scheme in which electrodes are drawn from both sides of the silicon wafer on the P-type and N-type doped regions respectively. The feature of this solution is: use a P-type substrate silicon wafer, and do N+ type doping on the surface to form a PN junction. Although the process is simple and the manufacturing cost is low, the conversion efficiency is also low. [0003] In order to improve the conversion efficiency of solar cells, people have proposed a variety of improvement schemes, one of which is the staggered back-contact solar cell manufacturing scheme, which is charac...

AI Technical Summary

Problems solved by technology

There are two problems with this battery solution. One is that only the carriers that can diffuse to the rear surface can be converted into electrical energy, and those carriers that cannot reach the rear surface due to their short lifespan cannot generate electricity.

The second is that the carriers need to diffuse from the front surface to the back surface, which makes the series resistance of the battery larger and affects the photoelectric conversion efficiency.

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