Optimization of p-i-n GaAs/AlGaAs Heterojunction Nanowire Solar Cell for Improved Optical and Electrical Properties

This study focuses on optimizing the performance of pin junction GaAs/AlGaAs heterojunction nanowire solar cell arrays using optoelectronic simulations. The research investigates the optimal doping for the GaAs core and AlGaAs shell, as well as the impact of shell thickness and junction positions on solar cell performance. Additionally, the study examines the effect of various surface effects, including the presence of surface traps, surface recombination velocities, and associated lifetime degradation. The research finds that high doping density is crucial for achieving appropriate band configuration and carrier extraction. It also highlights that having a larger doping density is more important than having a larger lifetime. The study observes that having a thick AlGaAs shell at the cost of the intrinsic GaAs region can be detrimental to the performance of the solar cell. Finally, the research examines the effect of different Aluminium compositions on photogeneration inside the nanowire and shows that having a high Aluminium composition can confine most photogeneration to inner GaAs regions, potentially allowing for thicker Aluminium shells, which can more efficiently prevent surface recombination.