Photo- and radioluminescence of lithium hafnate Li2HfO3

Photoluminescence, excitation and pulse cathode luminescence spectra, and decay kinetics of lithium hafnate Li2HfO3 were investigated at temperatures 300 and 7.5 K. Time-resolved luminescence spectra were excited with synchrotron radiation in UV–VUV range. Strong emission with the peak position at 4.42 eV and with the decay time in μs range was revealed at T = 7.5 K. The emission was attributed to radiative decay of self-trapped excitons (STE). The features observed in the excitation spectra at 6.6 eV were likely to take place because of the exciton formation, with inter-band transitions dominating at 6.7 eV. Crystal structure defects underpin the luminescence spectra formation at room temperature in the frame of vacancy model.

► The citrate technique for fine-dispersed Li2HfO3 scintillator.
► Radioluminescence and photoluminescence in VIS, UV and VUV ranges have been recorded.
► The luminescence centers are self-trapped and defect bond excitons.
► The particle size influences on the luminescence properties.