Improved Performance in Mirror-Assisted Back-Contact CMOS Photovoltaic Devices

Improved performance in CMOS interdigitated back-contact photovoltaic devices (IBC-PVs) is demonstrated by utilizing interdigitated junctions and a back metal reflector to simultaneously achieve large total junction area, uniform series resistance, and high optical back reflection. Enhanced ultimate efficiency of 20.33% is experimentally obtained from a 35-μm thick CMOS IBC-PV with a junction period of 7.2 μm under 980-nm illumination. Since the proposed IBC-PVs are implemented by standard bulk CMOS process, it can be easily integrated with other microelectronics to realize a self-power system for a variety of applications.