Detection of narrow linewidth acceptor peaks with p-type conduction in phosphorous implanted ZnMgO thin films

RF sputtered p-type ZnMgO films were successfully prepared by doping phosphorus ions using plasma immersion ion implantation technique for different implantation duration 10-70 sec and subsequent rapid thermal annealing at temperature range 700-1000 °C. Low-temperature (15 K) photoluminescence spectra revealed a highly dominating acceptor-bound exciton peak at 3.36 eV with minimum FWHM of 0.006 eV using Gaussian fitting for the sample implanted for 70 sec and annealed at 900 °C. Donor-bound-acceptor (DAP), free-electron-acceptor (FA), inelastic exciton-exciton scattering (XX) and free exciton (FX) peaks also appeared at 3.24, 3.28, 3.37 and 3.66 eV respectively. Room temperature Hall measurement system showed p-type conductivity for the implanted samples annealed at 800 and 900 °C. The highest hole concentration of 4.19×10¹⁶ cm^-3 was achieved with mobility value of 5.4 cm2V^-1S^-1. The P_Zn-2V_Zn complex which was a shallow acceptor in ZnMgO, responsible for p-type conduction in ZnMgO films. X-ray diffraction spectra confirmed the presence of the 002 peak for all the samples. Scanning electron microscopy measurement demonstrated the formation of homogenous surface with large size of dense grains of implanted ZnMgO film after annealing at 900 °C. The achievement of p-type Zn_0.85Mg_0.15O paves the way for the application of ZnMgO in the design of ultraviolet superlattice or quantum-well lightemitting diodes and other optoelectronic devices.