Effect of Rear Contact Coverage and Improvement of Efficiency of Crystalline p-Si Solar Cell Compared to State of Art PERC Cell

A device simulation model for localized contact rear side oxide-passivated solar cell was developed to study the effects of rear contact coverage and fixed charge density dependent field-effect passivation on the performance of a p-Si solar cell. Models describing hetero-interface physics related to metal-semiconductor, metal-oxide-semiconductor junctions and interface recombination are considered in the simulation, results of which are verified with the reported experimental data. A detailed analysis of the effect of surface passivation is presented and an analytical design with optimized set of parameters is outlined for fabricating the cell. The results show that the efficiency of the solar cell can be substantially enhanced by controlling parameters such as the ratio between localized back contact to the non-contact area and the fixed charge density at the oxide-interface. A maximum efficiency of ~ 24.5% for a crystalline p-Si solar cell with a comparatively lower lifetime can be obtained by a suitable choice of the design parameters with an added suitable choice of doping concentration in the emitter and absorber and the oxide layer thickness.