Method for preparing silicon band by direct forming and silicon wafer direct forming device

Abstract

The invention discloses a method for preparing silicon tape by direct forming. An alternating magnetic field is applied to the solid-liquid interface region between a silicon wafer and a silicon melt, and an induced current is formed in the silicon melt at the front of the solid-liquid interface. The joint effect of magnetic field and induced current forms a vertical solid-liquid interface at the solid-liquid interface and points to the electromagnetic extrusion force inside the silicon melt, and adjusts the magnitude of the electromagnetic extrusion force so that the electromagnetic extrusion force completely offsets the narrow edge of the silicon wafer The inward surface tension at the solid-liquid interface enables the flexible electromagnetic force to constrain and stabilize the shape of the solid-liquid interface, so that the silicon melt constrained by the flexible electromagnetic force is shaped and continuously solidified, and then the solidified strip-shaped silicon slab continues Pull out, directly prepared with silicon. The invention also discloses a silicon wafer direct forming device, which includes a silicon material melting and heat preservation device, a feeding device, a direct pulling dummy device and a silicon-taped soft-contact forming device, which can directly prepare a silicon wafer, realize clean production, and reduce silicon wafer defects. Realize large-scale direct production of industrial applications with silicon.

Description

technical field [0001] The invention relates to a photovoltaic material preparation process and device, in particular to a silicon material preparation process and device, which are applied to the preparation of solar-grade silicon bands. Background technique [0002] Today, with the rapid development of photovoltaic technology and micro-semiconductor inverter technology, solar cells produced by silicon crystals can directly convert solar energy into light energy, realizing the beginning of a green energy revolution. The silicon wafers used in traditional solar cells are cut from silicon ingots. Due to the limitations of the current wire saw technology, about 30% of the silicon material will be lost when the silicon ingots are processed into silicon blocks, and silicon blocks are processed into silicon wafers. 34-50% of the silicon material will be lost, and the cut silicon wafers need to be inspected and screened, and subsequent processes will also cause losses. Therefore,...

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Problems solved by technology

[0004] In order to solve the problems of the prior art, the object of the present invention is to overcome the defects of the prior art, provide a method for preparing silicon strips by direct forming and a direct forming device for silicon wafers, constrain the solid-liquid interface in the forming process of silicon wafers, and then stabilize Control the shape of the solid-liquid interface, directly prepare strip silicon, eliminate the pollution of silicon melt during the production process, reduce the defects of silicon wafers, improve the photoelectric conversion efficiency of silicon wafers, and realize the industrial application of large-scale direct production of strip silicon

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