Single GaAs nanowire photovoltaic devices under very high power illumination

GaAs nanowire pn-diodes were used for single nanowire radial and axial photovoltaic device fabrication. In this study the performance under very high illumination power is measured and analyzed in terms open circuit voltage, and efficiency. It is found that GaAs nanowire photovoltaic devices can be operated under very high power of up to 120 W/cm² (λ = 532 nm) without detectable degradation. The short circuit current increases directly proportional to the illumination power while the open circuit voltage steadily increases up to the highest illumination. This study shows that both axial and radial nanowire pn-junctions are suitable for sun light conversion with very high concentration ratio ( >; 1,000).