"Research, development and application of several key technologies for purifying solar grade silicon based on physical metallurgy" passed acceptance

On December 14, the Fujian Provincial Department of Science and Technology organized an expert acceptance of the major provincial science and technology special topic “Development and application of certain key technologies for the purification of solar grade silicon based on physical metallurgy methods” that was presided over by the researcher of Fujian Institute of Materials Structure of the Chinese Academy of Sciences, Huang Feng. . After listening to the work report of the project team, the expert group believed that the project had completed various research and development tasks as planned and unanimously agreed to pass the project acceptance.

This project addresses the research, development, and application of several key technologies for purifying solar grade silicon based on physical metallurgy and has achieved a series of results: based on the fundamental principles of thermodynamics, the different thermodynamic conditions required for the removal of boron and phosphorus have been determined. The new boron technology and the independent development of high-vacuum phosphorus removal and electron beam removal of phosphorus technology; built a 50 kg class solar grade silicon material experimental process line, formed a complete process route with independent intellectual property rights. The obtained silicon material has a boron content of 0.5-0.6 ppm, a phosphorus content of 0.2-0.3 ppm, a purity of 6 N, and a minority lifetime of 16 μs, which meets the requirements of the project's mission statement. The silicon material obtained by this special technique receives the internal and external batteries of the province. The company uses mature production processes to produce solar cells with an average efficiency of 15.5% on standard-sized single wafers; and establishes a standard analysis and test platform for solar grade silicon materials, and a research platform for the physical mechanism of semiconductor photovoltaic materials and devices, becoming the first domestic company to pass The silicon material testing laboratory certified by CMA has conducted more than 700 testing services for silicon material companies inside and outside the province, providing scientific basis for improving and upgrading silicon material purification technology.

This special topic has important application prospects in reducing energy consumption and solving environmental issues in the solar industry. During the implementation of the project, the researchers used the relevant results to guide the cooperative enterprises to carry out technological improvement and achieved the expected results; the project applied for 5 national invention patents and published 9 SCI papers. One local standard and three corporate standards have been formulated.

Director of the Fujian Institute of Materials and Construction, Director of the Institute of Material Construction, Mao-Xiang Hong and Deputy Director Lin Wenxiong, as well as the R&D personnel of the Science and Technology Department and project team participated in the acceptance meeting.