Vacuum growth of uniform semiconductor films on large area flat substrates for photovoltaics

Computer simulations are utilized to address the problem of film uniformity on large-area substrates present in a vacuum-growth process. The problem is approached by optimizing different source-substrate geometries. The simulations indicate that an optimized arrangement of four disc sources results in a uniform area of 24 cm² for ±0.05% variation in the incident flux with material utilization of 2.2% for a given source-substrate situation. Simulations of line sources were also carried out. Inclined modified dual in-line sources, each 30 cm long, resulted in a uniform area of 86.57 cm² for ±0.25% variation in the incident flux with material utilization of 6.76%. The possibility of substrate size scale-up is also considered