Preparation of silicon target material by adding Al-B master alloy in directional solidification

17th IUMRS International Conference in Asia

Li, Pengting^1,2 ; Wang, Kai^1,2 ; Ren, Shiqiang^1,2 ; Jiang, Dachuan^1,2 ; Tan, Yi^1,2

School of Materials Science and Engineering, Dalian University of Technology, Dalian

116024, China^1

Key Laboratory for Solar Energy Photovoltaic System of Liaoning Province, Dalian

116024, China^2

关键词: Al-B master alloy;    Industrial production;    Mean concentrations;    Measured values;    Molten silicon;    Segregation coefficients;    Silicon targets;    Technical support;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/182/1/012002/pdf
DOI  :  10.1088/1757-899X/182/1/012002

来源: IOP

【 摘 要 】

The silicon target material was prepared by adding Al-6B master alloy in directional solidification. The microstructure was characterized and the resistivity was studied in this work. The results showed that the purity of the silicon target material was more than 99.999% (5N). The resistivity was ranges from 0.002 to 0.030 Ω•cm along the ingot height. It was revealed that the particles of AlB2in Al-6B master alloy would react spontaneously and generate clusters of [B] and [Al] in molten silicon at 1723 K. After directional solidification, the content of B and Al were increasing gradually with the increase of solidified fraction. The measured values of B were in good agreement with the curve of the Scheil equation below 80% of the ingot height. The mean concentration of B was about 17.20 ppmw and the mean concentration of Al was about 8.07 ppmw after directional solidification. The measured values of Al were fitting well with the curve of values which the effective segregation coefficient was 0.00378. It was observed that B co-doped Al in directional solidification polysilicon could regulate resistivity mutually. This work provides the theoretical basis and technical support for industrial production of the silicon target material.