Surface morphology and photoluminescence characteristics of Eu-doped YVO4 thin films

Surface morphology and crystallinity of YVO4:Eu3+ thin films have influenced on the photoluminescence characteristics. The YVO4:Eu3+ films have been deposited on Al2O3 (0 0 0 1) substrates using pulsed laser deposition method. The films were grown at the various substrate temperatures and oxygen pressures. The substrate temperatures were changed from 500 to 700 °C and the range of oxygen pressures was 100-400 mTorr. The crystallinity and surface morphology of the films were investigated using X-ray diffraction (XRD) and atomic force microscope (AFM), respectively. The results of XRD showed that YVO4:Eu3+ films had zircon structure and AFM study revealed that the films consisted of homogeneous grains ranging from 100 to 400 nm depending on the deposition conditions. The photoluminescence spectra were measured at room temperature using a luminescence spectrometer and the emitted radiation was dominated by the red emission peak at 620 nm radiated from the transition of 5D0-7F2. The crystallinity, surface morphology and photoluminescence spectra of thin-film phosphors were highly dependent on the deposition conditions, in particular, the substrate temperature and oxygen pressure. The surface roughness and photoluminescence intensity of the films showed similar behavior as a function of substrate temperature and oxygen pressure.