X-ray and pulsed electron beam excited luminescence and optical absorption in KTaO3 crystals

Abstract

Pulsed electron beam excited time-resolved transient absorption and luminescence have been studied in nominally pure and Li- doped KTaO3 single crystals. It is found that under electron beam excitation in nominally pure KTaO3 the absorption bands peaks at ∼0.8 eV, ∼1.1 eV and 1.7 eV whereas in KTaO3:Li at ∼1.1 eV and ∼1.7 eV. The transient absorption decay varies over the spectrum thus revealing several short-lived centers. The main luminescence peak is centred at ∼2.7 eV in all KTaO3 specimens. Luminescence decay kinetics observed for the two bands slightly differ indicating different kinds of excited states are involved. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.