3 January 1996 Study of photoinduced charge transfer in SrTiO3: luminescence, photoconductivity and photo-EPR
Author Affiliations +
Proceedings Volume 2706, Tenth Feofilov Symposium on Spectroscopy of Crystals Activated by Rare-Earth and Transitional-Metal Ions; (1996) https://doi.org/10.1117/12.229167
Event: Tenth Feofilov Symposium on Spectroscopy of Crystals Activated by Rare Earth and Transitional Ions, 1995, St. Petersburg, Russian Federation
Abstract
A study of photoluminescence, photo-EPR, and of photoconductivity was carried out on SrTiO3 and Sr1-xCaxTiO3 (x equals 0.007) crystals containing a small amount of Cr. As a result, the location of Cr electronic levels in the band gap was found, Cr3+ being a donor located at 1.85 eV below the CB bottom and Cr4+ being an acceptor at 1.4 eV above the VB top. In accordance with this scheme, it was shown that: (1) Photons with energies exceeding 1.85 eV excite Cr3+ R luminescence in the course of the events; h(nu) exc + Cr3+ yields e + Cr4+ yields Cr3+(2E) + phonons yields Cr3+(4A2) + h(nu) R. (2) Excitation with photon energies above 1.4 eV converts Cr4+ to Cr$3+):h(nu) exc + Cr4+ yields h + Cr3+. (3) A band with low energy threshold at 2.1 eV is observed both in excitation spectra of R luminescence and of photoconductivity. The specific character of photoluminescence excitation manifests itself in a number of interesting observations: (i) Strong increase of steady-state R luminescence intensity under IR irradiation additional to excitation in the visible. (ii) IR induced transient R luminescence caused by previous irradiation in the visible. (iii) Very long tails on the time scale of 1000s in R luminescence decay with weak dependence on temperature from 2 K to 78 K.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
S. A. Basun, S. A. Basun, U. Bianchi, U. Bianchi, V. E. Bursian, V. E. Bursian, Alexander A. Kaplyanskii, Alexander A. Kaplyanskii, W. Kleemann, W. Kleemann, L. S. Sochava, L. S. Sochava, V. S. Vikhnin, V. S. Vikhnin, } "Study of photoinduced charge transfer in SrTiO3: luminescence, photoconductivity and photo-EPR", Proc. SPIE 2706, Tenth Feofilov Symposium on Spectroscopy of Crystals Activated by Rare-Earth and Transitional-Metal Ions, (3 January 1996); doi: 10.1117/12.229167; https://doi.org/10.1117/12.229167
PROCEEDINGS
10 PAGES


SHARE
RELATED CONTENT


Back to Top