Effect of substrate temperature on structure and luminescence properties of YVO4:Eu3+ thin films grown by PLD

Abstract

YVO4:Eu3+ thin films were deposited by pulse laser deposition at substrate temperatures of 200, 300 and 400 °C. The oxygen deposition background pressure was also changed from 20 to 85 mTorr at a substrate temperature of 400 °C. The films deposited at the higher temperatures showed a tetragonal phase in consistent with the standard JCPDS card 17-0341. The X-ray diffraction patterns obtained from the 200 °C sample showed only a very small peak at the (200) orientation. The other phosphor thin film showed an improved crystalline structure when the temperature was increased. Scanning electron microscope images indicated larger particles on the surface at the higher temperatures. Atomic force microscopy results showed smooth surfaces with small particles at lower temperatures and an increase in surface roughness at higher temperatures due to the improvement in crystallinity. The photoluminescence showed the typical emission peaks of Eu3+ in the red region at 594 and 618 nm attributed to the 5D0–7F1 and 5D0–7F2 transitions. The peaks at 652 and 699 nm corresponding to the 5D0–7F3 and 5D0–7F4 transitions were also observed. The spectra showed an increase in PL intensity when the deposition temperature and oxygen pressure were increased.