Impact of HfO₂ as a Passivation Layer in the Solar Cell Efficiency Enhancement in Passivated Emitter Rear Cell Type

We report the simulation of high-efficiency c-silicon Passivated Emitter Rear Contact (PERC) type solar cell structure with rear side passivated with HfO₂ as a passivating material. Variation in the half length of pyramid has been carried out to investigate its effect on the solar cell electrical characteristics such as fill factor (FF), open circuit voltage (V_oc) and efficiency. Aluminum back Surface Field (Al-BSF) and PERC type solar cell with Al₂O₃ passivation layer structures were also modeled for comparison. Effect of variation in passivation layer (HfO₂) thickness (10 and 15 nm) and permittivity (k = 14 and 25) on the solar cell electrical characteristics has been investigated. Result shows the efficiency improvement in the PERC solar cell with HfO₂ passivation layer by 0.5941% and 0.983% as compared to the Al-BSF and PERC with Al₂O₃ passivation layer at 8 μm pyramid half length. Increased series resistance and reduced FF has been observed with the incorporation of passivation layer at the solar cell structure. Negligible effect of passivation layer thickness has been observed on the solar cell electrical parameters whereas the permittivity value does have significant effect.