Carrier Selective Back Contact (CSBC) Solar Cell Using Transition Metal Oxides

摘要

A solar cell with transition metal oxides as back contact carrier selective layers has been conceptualized and analyzed in this paper. We term such a solar cell as a carrier selective back contact solar cell (CSBC-SC). A CSBC-SC has both contacts on the rear and thus circumvents the trade-off between surface passivation, light trapping, and charge extraction, necessary for the front surface development of a high-performance CSC solar cell with contacts on both sides (frontrear CSC-SC). Further, it also eliminates optical losses due to metal shading and parasitic absorption occurring in low bandgap thin film layers. Therefore, an idealized CSBC-SC provides superior performance as compared to a front-rear CSC-SC, while simultaneously reducing the complexity of design rules. In this paper, the analysis of a CSBC-SC has been performed through an integrated multi-scale electro-optical numerical model developed in the commercial simulator Sentaurus. Results show that a nonideal CSBC-SC outperforms a front-rear CSC-SC for rear surface recombination velocities (SRV) below 100 cm/s and bulk lifetime values above 100 microseconds. However, a CSBC-SC shows significant sensitivity to front SRV and the values need to be below 10 cm/s to outperform a front-rear CSC-SC.