Investigation of Bandgap Modulation of Al Doped ZnO Nanowires Grown on AZO Seed Layer for Photovoltaic Devices

Abstract

Zinc oxide (ZnO) nanowires (NWs) are gaining importance in diverse applications because of their excellent electrical and optical properties. The modulation of the ZnO NW bandgap by doping further enhances their potential. In this work, we have analyzed this bandgap tuning and have hydrothermally synthesized Aluminum (Al) doped and undoped ZnO NWs on Al doped ZnO (AZO) seed layer. The photoluminescence (PL) properties of the NWs have been investigated and it is found that doping increases the optical bandgap of the NWs and also enhances the near-band-edge (NBE) emission while suppressing defect emissions in the visible region. Al doping also increases the free carrier concentration and subsequent electrical conductivity of the NWs. The improvement in the optical and electrical properties of the Al doped ZnO NWs makes them a promising candidate for applications in photovoltaic (PV) devices.