Raman scattering and photoluminescence of As ion-implanted ZnO single crystal

Abstract
We have converted the surface of undoped ZnO bulk into the As-doped p- ZnO layer by means of the As ion implantation method. After postimplantation annealing, the As-related properties were investigated by using Raman scattering and photoluminescence(PL) experiments. The Raman spectrum shows that the E 2 high peak obtained from the As-doped p-ZnO shifted toward the higher energy side of 0.55 cm−1 in comparison with that of the undoped ZnO bulk. This result is related to the stress increment of the sample surface due to the As implantation. After the As-implanted p- ZnO annealed at 800 °C, the PLspectroscopy reveals the neutral acceptor bound exciton emission (A ∘ ,X) at 3.3589 eV. This emission shows a tendency to quench the intensity and extend the emission linewidth with increasing temperatures. Also, two As-related peaks associating with recombination emissions between free electrons and acceptor holes were observed at 3.3159 and 3.2364 eV. In addition, the I–V characteristic curves of the p–n homojunction fabricated with the As ion implantation method clearly have shown the behavior of the diode.