High Efficiency Ge Bottom Cell for GaInP2/GaAs/Ge Three-Junction Tandem Solar Cell

Analyze the impacts of structure and device process of Ge solar cell on open-voltage,light current density, and fill factor.By controlling the surface-recombination velocity,reduction of emitter thickness, and improvement of device process,demonstrate Ge solar cell with open-voltage of 2875mV,short-circuit current density of 73.13mA/cm2,and efficiency of 7.35%