Localizing nature of photo-excited states in SrTiO3

The absorption and luminescence measurements of SrTiO3 are made between room temperature and 10 K. From the absorption spectra, it is shown that this material has an indirect band gap energy of 3.16 eV at 10 K. No exciton absorption is observed. The luminescence spectra indicate the existence of STE. A time-resolved luminescence measurements revealed that localizing of electrons and holes plays an important role in the kinetics of photo-excited states. (C) 2000 Elsevier Science B.V. All rights reserved.