Investigation of p-CuO/n-Cu₁-ₓInₓO core/shell nanowire structure performance in UV photodetectors

Abstract

We report on the formation of a pn junction through the use of CuO/Cu1-xInxO core/shell nanowire (NW) structures for application in photodetectors. The CuO NWs arrays were prepared by simple heat-treatment of Cu foil at 500 degrees C in ambient air in a furnace. The Cu1-xInxO nanocomposites synthesized by reflux condensation were drop-casted onto prepared p-CuO NWs arrays to form a core/shell pn junction. Investigation of Cu1-xInxO nanocomposites containing differing amounts of In2O3 (from pure CuO nanocomposites to nanocomposites including 80% In2O3) exhibits the changed electrical polarity that varies from p-type to n-type. Following the formation of the indium tin oxide (ITO) electrode on the Cu1-xInxO shell surface, the observed current-voltage (I-V) curves clearly showed typical rectifying p-n diode characteristics. Our suggested p-n heterojunction yielded a 3.48-fold increase in photocurrent level upon Xe lamp illumination when compared with current in the dark state. Additionally, the fabricated core/shell p-n junction exhibited a photoresponsivity of 0.045 A/W at 374 nm.