Solar cell and heat treatment process thereof

Abstract

The embodiment of the invention discloses a solar cell and a heat treatment process thereof. The method comprises the following steps of: (a) screening solar cells of which the conversion efficiency is lower than 18 percent and a packing factor is over 70 percent from the solar cells subjected to printing and sintering; (b) annealing the screened solar cells at low temperature; (c) screening the solar cell of which the packing factor is decreased from the solar cells subjected to low-temperature annealing; (d) re-sintering the screened solar cell; and (e) screening the solar cells of which the conversion efficiency is lower than 18 percent from the re-sintered solar cells and returning to the (b) until a large part or all screened solar cells meet the requirement. In the embodiment of theinvention, the low-temperature annealing and re-sintering processes are circularly carried out; the defects of a substrate material can be restored by using the low-temperature annealing process; thedefects generated by the low-temperature annealing can be restored by using the re-sintering process; and two treatment processes are mutually matched and the screening is carried out layer by layer,thus the amount of low-efficiency cells is greatly reduced and economic benefit is improved.

Description

technical field [0001] The invention relates to the field of production and processing of solar cells, and more specifically relates to a solar cell sheet and a heat treatment process thereof. Background technique [0002] A solar cell, also known as a photovoltaic cell, is a semiconductor device that converts the sun's light energy directly into electrical energy. Because it is a green product, does not cause environmental pollution, and is a renewable resource, solar cells are a new energy source with broad development prospects in today's energy shortage situation. At present, more than 80% of solar cells are made of crystalline silicon (monocrystalline silicon and polycrystalline silicon) materials. Therefore, the preparation of high-efficiency crystalline silicon solar cells is of great significance for large-scale utilization of solar power generation. [0003] At present, the production process of crystalline silicon solar cells has been standardized, and its main st...

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Problems solved by technology

[0010] In the actual production process, it is found that a certain proportion of cells with low conversion efficiency often appear in the cells produced by the above method. Here, solar cells with a conversion efficiency lower than 18% are called extra-low efficiency cells or Inefficient tablets

In the prior art, the method of processing the above-mentioned low-efficiency chips is to screen out the above-mentioned low-efficiency chips after sorting and testing, and directly pack them into the warehouse according to the low-efficiency products outside the standard. Efficiency, reduced economic benefits

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