Phosphorus gettering in low-cost cast monocrystalline silicon for heterojunction solar cells.

Phosphorus gettering using tubular diffusion furnaces was performed on n-type cast monocrystalline silicon wafers to assess its impact on wafer quality and the conversion efficiency of heterojunction solar cells. A comprehensive analysis of temperature, duration, and cooling rate in the diffusion process was conducted. The optimal parameters were identified at a temperature of 850 °C for 30 min, with a cooling rate of 5 °C/min down to 500 °C. This gettering process effectively reduced interstitial iron concentration, improved minority carrier lifetime, and increased the average efficiency of HJT cells by an absolute 0.4 %, with a 1.1 % increase for those made from bottom wafers with high metal concentration. [ABSTRACT FROM AUTHOR]