Hybrid GaAs nanowire-polymer device on glass: Al-doped ZnO (AZO) as transparent conductive oxide for nanowire based photovoltaic applications

Al-doped ZnO (AZO) is pursued as an alternative low-cost transparent conductive oxide (TCO) to expensive ITO. Atomic layer deposition grown AZO films showing resistivity of 5 x 10-3 Ωcm and transmittance > 85% in the visible region are reported. Au-assisted GaAs nanowires are grown directly on an optimized AZO coated glass and a GaAs nanowire-polymer hybrid device on glass is demonstrated which confirms that the as-grown GaAs nanowires form a perfect ohmic contact to AZO film. The device shows that AZO can be used as transparent electrode as well as low-cost growth platform for GaAs NWs. Finally, a simple device idea is proposed to fabricate optically transparent GaAs nanowire based solar cells on low-cost glass.