Luminescence of borates with yttrium and lutetium cations

Abstract

This paper reports on the results of an investigation into the luminescence properties of yttrium and lutetium borates, as well as the Y0.35 Lu 0.65 BO 3 solid solution, under excitation with the synchrotron radi� ation in the Xray and ultraviolet spectral ranges. It has been shown that there exists an intrinsic luminescence band in the ultraviolet spectral range 260-270 nm due to the luminescence of selftrapped excitons. It has been found that the kinetic characteristics of this band depend on the density of the exciting synchrotron radi� ation. A number of luminescence bands have been observed in the longwavelength range due to the presence of defects in the crystal structure of borates. It has also been shown that the energy transfer to impurity centers has a recombination nature and can also occur through impact ionization of defects. It has been revealed that, for the solid solution, the excitation efficiency of the luminescence of defects increases under interband exci� tation, which can be associated with the limited separation of the components of an electron-hole pair as a result of shortrange order disturbance in the structure of the solid solution.