Method for preparing efficient ingot polycrystalline silicon and special monocrystalline silicon wafer

Abstract

The invention relates to a method for preparing an efficient ingot polycrystalline silicon ingot. The method comprises the following steps: before the start of a conventional ingot casting process, putting treated monocrystalline silicon wafers to the bottom of a polycrystalline ingot casting furnace, and then performing ingot casting by using a common process to obtain a small-grain ingot polycrystalline silicon ingot. Meanwhile, the invention also provides a monocrystalline silicon wafer special for preparing efficient ingot polycrystalline silicon, and the monocrystalline silicon wafer comprises a silicon wafer body and is characterized in that a silicon oxygen layer and a silicon nitrogen layer are arranged at two sides of the silicon wafer body respectively, the thickness of the silicon wafer body is 0.18mm, the thickness of the silicon oxygen layer is 0.1-0.2mm, and the thickness of the silicon nitrogen layer is 0.2-0.3mm. By paving the treated monocrystalline silicon wafers to the bottom of the polycrystalline ingot casting furnace, and because the monocrystalline silicon wafer with the silicon oxygen layer and the silicon nitrogen layer is coated on two surfaces of these monocrystalline silicon wafers, the monocrystalline silicon wafers achieve an induction effect to form small-particle grains so as to inhibit dislocation, thereby reducing in-vivo defects of a polycrystalline material and finally improving the efficiency of a battery.

Description

technical field [0001] The invention relates to a method for preparing high-efficiency ingot polycrystalline silicon ingots and special monocrystalline silicon, which are mainly suitable for suppressing dislocations and reducing defects in the production process of ingot polycrystalline silicon in the photovoltaic industry, and belong to the technical field of solar cells. Background technique [0002] Crystalline silicon solar cells account for about 80% of the entire photovoltaic market and are in a dominant position, but there are also a series of problems such as high manufacturing costs and uneven quality of raw silicon materials. It is predicted that silicon materials will continue to develop in the direction of high efficiency and low cost in the future. [0003] Compared with monocrystalline silicon materials, ingot polycrystalline silicon has attracted widespread attention due to its low cost and large output. However, there are a large number of defects in polycrys...

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Problems solved by technology

However, the quartz sheet in this method will introduce impurity pollution when casting polycrystalline, which will reduce the pass rate of the entire crystal ingot and reduce the output.

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