We made Thermally Stimulated Conductivity (TSC), Thermoluminescence (TL) and Electron Spin Resonance (ESR) measurements on single crystals of potassium tantalate in the temperature range 4.2-290 K. We revealed two sorts of O - shallow hole centers which are responsible for Photoconductivity (PC) and Photoluminescence (PL) enhancement. Both O - centers were identified by their ESR spectra. We show that these centers serve as radiative electron-hole recombination centers. The measurements of TSC and TL after UV irradiation revealed several glow peaks at temperatures 18-30 K and 65-70 K. Both TSC and TL are attributed to the thermal ionization of the same shallow donor centers related with oxygen vacancies. Experimental data were treated in a simple one-trap/one-recombination center model, which takes into account the presence of "thermally disconnected" deep electron traps.
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Titolo: | Shallow traps in pure KTaO3 crystals |
Autori: | |
Data di pubblicazione: | 2002 |
Rivista: | |
Abstract: | We made Thermally Stimulated Conductivity (TSC), Thermoluminescence (TL) and Electron Spin Resonance (ESR) measurements on single crystals of potassium tantalate in the temperature range 4.2-290 K. We revealed two sorts of O - shallow hole centers which are responsible for Photoconductivity (PC) and Photoluminescence (PL) enhancement. Both O - centers were identified by their ESR spectra. We show that these centers serve as radiative electron-hole recombination centers. The measurements of TSC and TL after UV irradiation revealed several glow peaks at temperatures 18-30 K and 65-70 K. Both TSC and TL are attributed to the thermal ionization of the same shallow donor centers related with oxygen vacancies. Experimental data were treated in a simple one-trap/one-recombination center model, which takes into account the presence of "thermally disconnected" deep electron traps. |
Handle: | http://hdl.handle.net/11571/106602 |
Appare nelle tipologie: | 1.1 Articolo in rivista |