Luminescence dynamics in ZnSeTe scintillators

ZnSeTe single crystals with 2 wt% of Te fabricated for application as scintillating material in radiation detectors are studied by means of photoluminescence spectroscopy. Time evolution of the luminescence spectra, which is found to be strongly dependent on thermal treatment in different environments, reveals competition between nonradiative recombination and channels of radiative recombination resulting in two strongly overlapping emission bands. The origin of the bands is interpreted by recombination involving defect complexes containing Zn vacancies. Stabilization of the complexes by doping ZnSe with isoelectronic Te is discussed. Influence of annealing in Zn on reduction of concentration of nonradiative recombination centers and stabilization of the defect complexes, which are employed in ZnSe scintillation detectors, is demonstrated.