Optical characterization of Er-doped ZnSe for scintillation applications

The effect of Er-doping of ZnSe crystals on luminescence and structural properties was investigated using low-temperature photoluminescence, X-ray luminescence, Raman and IR spectroscopies. It was found that Er dopant atoms with the concentration in the solid phase of about 10(-3) wt.% lead to a substantial disordering of initial crystalline structure. The mentioned processes manifest in substantial decrease of the amplitudes of corresponding vibrational modes and increase of their FWHM in first-order Raman spectra of Er-doped ZnSe crystals. Also, Er-doping stimulates an appearance of additional absorbance bands in IR transmittance spectra. However, Er-doping leads to substantial increase of the efficiency of photoluminescence and X-ray luminescence that is very important for scintillation application. In this case, the luminescence is mainly caused by recombination via defect centers which contain Er atoms incorporated in the ZnSe lattice in different electronic configurations. (C) 2014 Elsevier B.V. All rights reserved.