Back Junction n-type Silicon Heterojunction Solar Cells with V2O5 Hole-selective Contact

In this work, a back junction solar cell design is explored for n-type crystalline silicon by using thermally evaporated V2O5 as a rear hole contact and n+ amorphous silicon (a-Si:H) as a front electron contact. Photoconductance measurements revealed an implicit open-circuit voltage (i-VOC) of 670 mV for the solar cell precursor (before metallization), achieved by maximizing the work function of V2O5 with a thin nickel capping layer. The VOC value of the finished device was lower than projected at 617 mV, most likely due to poor passivation of the active area perimeter. Nonetheless, an efficiency of 14.2% was achieved (in polished substrates), proving the potential of such a novel structure.