A method for preparing an inverted octagonal pyramid-shaped patterned silicon substrate

Abstract

The invention relates to a preparation method for an inverted octagonal-frustum-shaped patterned silicon substrate, and aims to solve the problems that pyramid-shaped and frustum-shaped patterned silicon substrates cannot be prepared through dry etching at present and a patterned silicon substrate with a high-index crystal face cannot be easily prepared through etching. The method comprises the steps: preparing a periodic silicon dioxide mask, performing wet etching and removing the silicon dioxide mask. The substrate has a high-exponential crystal face, and the root-mean-square roughness of the high-exponential crystal face is about 10 times higher than that of a low-exponential crystal face and about 4 times higher than that of a (100) crystal face. Moreover, the rough surface can reflect incident light for multiple times and increase an optical path, so that the light reflectivity of the surface is reduced. Therefore, compared with an inverted pyramid structure only having a low-index crystal face, the inverted octagonal-frustum-shaped patterned silicon substrate has better light capture capability. The method is applied to the field of preparation of the patterned silicon substrate.

Description

technical field [0001] The invention relates to a method for preparing an inverted octagonal pyramid-shaped patterned silicon substrate. Background technique [0002] In silicon solar cells, the role of silicon is to absorb solar energy and convert it into electricity, so it is necessary to reduce the reflection of sunlight on the silicon substrate. At present, the most commonly used methods for reducing the surface reflectance of solar cells include surface anti-reflection coating and surface roughening and texturing. Among them, the surface roughening treatment not only increases the optical path of the incident light, but also increases the number of reflections of the incident light, thereby reducing the reflectivity of the light, and achieving the purpose of improving the efficiency of the solar cell. [0003] At present, KOH wet etching and ICP dry etching are often used to roughen the surface of silicon substrates, but the anisotropy of these two methods is weak, and...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the current dry etching method cannot prepare pyramidal and pyramidal patterned silicon substrates and it is difficult to etch to prepare patterned silicon substrates with high index crystal planes, and to provide an inverted octagonal pyramidal patterned silicon substrate Bottom preparation method

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