Influence of Different Metals Back Surface Field on BSF Silicon Solar Cell Performance Deposited by Thermal Evaporation Method

This paper presents comparison of thermal evaporation method based passivation and BSF formation with different materials (Au, Al, and Cu). Silicon solar cells with different rear surface contact using these materials were fabricated. A comprehensive comparison of the samples have been carried out to find better back surface contact regarding the efficiency by investigating I-V characteristics, fill factor, external quantum efficiency and carrier diffusion length and lifetime, etc. Experimental data revealed that Cu based back surface contact has maximum output efficiency of about 13.73%, whereas Au shows maximum external quantum efficiency of about 86%. Moreover, use of Al shows the maximum carrier diffusion length 97.2μm and highest carrier lifetime of 3.5μs with overall cell efficiency of 12.90% indicating that Al is a promising material for back contact for n + -p-p + back surface field silicon solar cell.