Influence of growth temperature of TiO2 buffer on structure and PL properties of ZnO films

A series of ZnO films with TiO2 buffer on Si (1 0 0) substrates were prepared by DC reactive sputtering. Growth temperature of TiO2 buffer changed from 100 °C to 400 °C, and the influence on the crystal structures and optical properties of ZnO films have been investigated. The XRD results show that the ZnO films with TiO2 buffer have a hexagonal wurtzite structure with random orientation, and with the increase of growth temperature of TiO2 buffer, the residual stresses were released gradually. Specially, the UV emission enhanced distinctly and FWHMs (full width half maximum) decreased linearly with the increasing TiO2 growth temperature. The results all come from the improvement of crystal quality of ZnO films.