On the Phosphorus Evaporation from Liquid Silicon by Knudsen Effusion Mass Spectrometry

Abstract Silicon refining for solar applications is intensively on demand, and removal of phosphorus from Si one the most challenging steps. Evaporation P liquid in a vacuum process efficient method Si, this research deals with insight mechanisms evaporation Si. In research, gaseous species evaporating dilute solutions silicon were studied experimentally, it was shown that evaporates form P, 2 , 4 3 SiP, SiP at elevated temperatures. Except other molecules detected experimentally first time, as new compound gas phase. Knudsen effusion mass spectrometry technique applied to characterize samples containing 100, 1250, 3000 ppmw phosphorus. The by isothermal polythermal experiments, up 1840 °C. vapor pressures various P-containing (P, P) 1442 °C measured function fraction silicon. Results indicated major part phosphides especially when sample temperature exceeds 1750 When initial 100 ppmw, about 71 pct means . are proposed, which depend melt composition temperature. It occurs through independently or via decomposition transient surface direct surface.