Spassky D.A.,University of Tartu |
Spassky D.A.,Moscow State University |
Nagirnyi V.,University of Tartu |
Savon A.E.,Moscow State University |
And 10 more authors.
Journal of Luminescence | Year: 2015
The luminescence and optical properties of promising cryogenic scintillator Li2MoO4 were studied in the temperature region of 2-300 K. The data on luminescence spectra and decay characteristics, excitation spectra, thermostimulated luminescence curves and spectra as well as transmission and reflectivity spectra are presented for the single crystals grown by two different procedures, the conventional Czochralski method and the lowerature gradient Czochralski technique. The bandgap of Li2MoO4 is estimated from the analysis of transmission, luminescence excitation and reflectivity spectra. Up to three luminescence bands with the maxima at 1.98, 2.08 and 2.25 eV are detected in the emission spectra of crystals and their origin is discussed. In the thermoluminescence curves of both studied crystals, two high-intensity peaks were observed at 22 and 42 K, which are ascribed to the thermal release of self-trapped charge carriers. The coexistence of self-trapped electrons and holes allows one to explain the poor scintillation light yield of Li2MoO4 at low temperatures. © 2015 Elsevier B.V. All rights reserved. Source