Host Sensitized Luminescence and Time-Resolved Spectroscopy of YVO4: Ho3+ Nanocrystals

Abstract

Rare earth doped phosphors have attracted much interest because of their high chemical durability and wide range of attractive applications. In this work, Ho3+ doped tetragonal YVO4 nanocrystals have been synthesized via a facile co-precipitation method. The phosphor was characterized by various methods including X-ray diffraction, photoluminescence, cathodoluminescence, time-resolved spectroscopy measurements. The frequency upconversion emission in the synthesized phosphor has been investigated under 800nm laser excitation. UV-excited photoluminescence (PL) and cathodoluminescence (CL) measurements were performed at room temperature (300K). A broad band which arises at ∼ 370-600nm is attributed to the relaxation of VO43− groups from conduction band to valence band. Under UV-excitation, the presence of a sharp band at 550nm due to the intra-4f transitions of the trivalent holmium ions suggests energy transfer from YVO4 host to RE ions. Luminescence measurements show that this material is suitable for field emission displays (FED) and fluorescent lamps. Also the conversion of UV radiation as well as IR radiation into the visible region suggests the application of this material for photon harvesting in solar cells.