Hybrid GaAs-Nanowire-Carbon-Nanotube Flexible Photovoltaics

A simple method is described for the preparation of carbon nanotube (CNT) composite films containing Au nanoparticles, which act as adatom collection agents promoting the growth of core-shell p-n junction GaAs nanowires (NW), according to the vapor-liquid-solid mechanism. This approach for composite film formation requires no covalent modification of the CNTs. GaAs NWs obtained are randomly aligned with respect to the CNT substrate in a densely packed arrangement. Nanohybrid films, incorporating coaxial GaAs NWs as the active, light-harvesting medium are used in the fabrication of photovoltaic cells, exhibiting conversion efficiencies up to 0.32%. Doping experiments confirm that conduction is not dominated by Schottky barriers at contact interfaces. The NW/CNT solar cells are shown to retain function following bending up to a curve radius of 12.5 mm, illustrating the potential of these novel materials in flexible device applications.