Generalized analysis of the impact of emitter sheet resistance on silicon solar cell performance

Emitter sheet resistance contributes significantly to the distributed series resistance of a solar cell. The series resistance ( R s ) impacts the fill factor (FF) and in turn affects the short-circuit current ( J sc ) and hence the efficiency. It is therefore, imperative to understand the properties of the emitter in order to achieve excellent ohmic contact. In this study, an analytical modeling of the dependence of open-circuit voltage ( V oc ), J sc , FF, and efficiency of a silicon solar cell on emitter sheet resistance was carried out. In order to better evaluate R s based on various metal grid designs, different grid models were used to investigate the resistive losses. And the one having the best match with the reference cell was incorporated in the simulation. It was found that for a typical three-bus-bar screen-printed silicon solar cell, the emitter sheet resistance should be in the 70–90 Ω/□ range.