Backside aluminisation effects on solar cell performance

In this work the effect if the back surface field (BSF) formation by high temperature treatment of backside aluminisation was analysed in silicon solar cells. Systematic I-V and spectral response (SR) characterisation shows an obviously superior performance of AI-diffused cells especially in the red near infrared region compared to those with conventional boron BSF. These findings along with the result of the performed XTEM, NRA (Resonance Nuclear Reaction Analysis), SIMS, and ECV (Electrochemical CV) analyses on the backside layer structure lead to the conclusion that the main contribution to the improvement, relative to the conventional reference sample, is the minority carrier lifetime enhancement by gettering effect in the AI-diffusion tail and the improved light trapping by backside roughening.