Short‐Lived Frenkel Defects in α‐Al₂O₃

Abstract

Abstract The fast luminescence, the transient absorption spectra, and the recombination kinetics are observed and investigated in α‐Al 2 O 3 . Absorption spectra reveal short‐lived bands at 2.75 and 2.15 eV. Their decay times remain the same (30 to 200 ns) in the temperature interval 80 to 293 K. They are found to be almost the same as the lifetime of the fast components of the luminescence band at 3.8 eV. They are expected to be due to interstitial aluminium ions. Experimental results argue for subthreshold creation of short‐lived Frenkel defect pairs in the cation sublattice of α‐Al 2 O 3 .