Effects of S incorporation on Ag substitutional acceptors in ZnO:(Ag, S) thin films

Abstract Ag–S codoped ZnO thin films have been fabricated on Si substrates by radio frequency (RF) magnetron sputtering using a thermal oxidation method. XRD and SEM measurements showed that the sample has hexagonal wurtzite structure with a preferential (002) orientation and the surface is composed of compact and uniform grains. Ag Zn – n S O defect complexes were observed in the Ag–S codoped ZnO films by XPS analysis. Low temperature PL spectra showed neutral acceptor bound exciton emission related to Ag Zn – n S O . The corresponding acceptor ionization energy of 150 meV is much lower than that of monodoped Ag (246 meV), which is favorable for p-type doping of ZnO.