Heteroepitaxy of III/V semconductor nanowire on silicon for novel solar cell applications
UC San Diego, US
Keywords: nanowire, heteroepitaxy, solar cell
Abstract:Semiconductor nanowires are one dimensional engineered structures that offer unique property controls, such as quantum confinement: on energy levels, density of states, recombination lifetimes, etc. The nanowires enable high surface area devices with engineerable absorption spectrum (size and composition) and fast charge separation due to the proximity of photoexcited carriers to charge-separating interface. The vertical nanowire arrays enable strong light absorption and separate the photon absorption and electron/hole transport pathway, which allow improved absorption and controlled structure/functionalization to direct charge separation, which increase the overall solar harvesting efficiency. Moreover, the growth of nanowires is virtually substrate free and allows integration to heterogeneous materials without lattice-matching constraints, which leads reduced cost and enhanced function integration. Herein, we report the direct growth of III/V semiconductor nanowires on silicon substrate using metal-organic chemical vapor deposition (MOCVD) and the fabrication of the vertical nanowire array based solar cells. The spectrum response and the photovoltaic effect are studies, and the efficiency to III/V material and device geometry correlation is also going to be reported.