Fabrication and Properties of Indium Tin Oxide/ZnO Schottky Photodiode with Hydrogen Peroxide Treatment

A transparent, efficient ZnO ultraviolet Schottky detector with indium tin oxide (ITO) as a metallic contact layer is fabricated on ITO-coated glass substrates by cw CO2 laser evaporation. The device behavior changes from near ohmic to Schottky in the current–voltage characteristics after hydrogen peroxide treatment on the ZnO surface with a fitted barrier height of 1.16 eV, an ideality factor of 2.31, and a leakage current of 3.1×10-7 A at -3 V bias. Photoluminescence (PL) data show the effect of hydrogen peroxide, and indicate that the surface defects are removed, and better diode characteristics are shown.