Hydrogen Plasma Treatment of ZnO Thin Films Grown by Using Pulsed Laser Deposition

Abstract

The effects of hydrogen plasma treatment were investigated by using the low temperature (10 K) photoluminescence spectra and Hall-effect measurements in the van der Pauw geometry. The hydrogen plasma introduced changes into both the electrical and the optical properties of ZnO. The UV emission intensity at 3.37 eV was increased by more than an order of magnitude when the ZnO sample was exposed to a hydrogen plasma for 1 min. From a comparison between the sample annealed at 800 degrees C and the sample annealed at 1000 degrees C, which have different initial defect concentrations, we demonstrate that the hydrogen doping process passivates the nonradiative recombination centers.