Luminescence properties of YPO4:Nd3+: a promising VUV scintillator material

Luminescence properties of YPO4:Nd3+ and partly LuPO4:Nd3+ have been studied under excitation by VUV synchrotron radiation and 6 keV electron beam in the wide range of temperature 9–300 K. Both compounds possess an intense wide-band VUV luminescence peaked at 189 nm which is due to 4f25d–4f3 electronic interconfigurational transitions in the Nd3+ ions. The efficient recombination mechanism of the energy transfer from the matrix to Nd3+ emission centres is responsible for both high light yield of VUV emission and for the appearance of the slow emission component in decay kinetics. At low temperature, the fine structure was revealed in emission and excitation spectra of Nd3+ 4f25d–4f3 luminescence in both systems. At temperatures below 160 K, the wide-band emission peaked at 420 nm was observed in YPO4 which was ascribed to the emission of self-trapped excitons.