Modeling of Increased Open Circuit Voltage through Localized Emitter Area on Silicon Solar Cells

A limited area p-n junction approach can increase the open circuit voltage (Voc) of silicon solar cells when the emitter recombination dominates. A limited area p-n junction silicon solar cell is designed and the effect of reducing emitter areas on the Voc, short circuit current (Jsc) and fill factor (FF) is studied using the 3-D simulator Quokka. This paper compares the modelling result of this approach on structures with different values of emitter recombination. It is concluded that voltage improvement can be achieved when the emitter dominates the total recombination. The result also shows that the current collection and FF can be maintained with an optimized unit cell design. The paper also extends the approach to thin (20 μm) solar cells, demonstrating the potential for Voc values up to 770 mV when excellent surface passivation is employed.