Influence of Electrical Design on Core–Shell GaAs Nanowire Array Solar Cells

Abstract

In this paper, we perform coupled optical and electrical simulation for core–shell junction GaAs nanowire array solar cells to obtain the important physical insights of how the cell efficiency is affected by various key parameters, including core–shell doping, junction position, carrier lifetime, and surface effect. Our study reveals that junction design in core–shell nanowires in terms of doping and geometry is largely restricted and affected by the small nanowire dimension, requiring different optimization from those of conventional planar solar cells. To take advantage of the radial p-n junction, high core and shell doping are essential to achieve effective radial carrier collection. Moreover, maintaining thin nanowire shell could effectively offset the detrimental surface effect for improved efficiency.