Al_2O_3단결정의 열자극 발광과 exo전자방출 = Thermally Stimulated Luminescence and Thermally Stimulated Exoelectron Emission of Al_2O_3 Single Crystal

다국어 초록 (Multilingual Abstract)

Simultaneous measurements thermally stimulated luminescence(TSL) and thermally stimulated exoelectron emission(TSEE) of Al_2O_3 single crystals irradiated with X-ray and UV have been studied over the temperature range from 300 to 500K.
Two glow peaks of the TSL are observed at 385 and 425K and the two TSSE glow peaks are observed at 375K and 450K after X-ray irradiation. The emission spectrum of the 385K TSL peak shows two bands emission at 310 and 410nm, whereas the 425K TSL peak exhibits 410nm emission band.
Experimental results suggest that the 385K TSL peak is due to the thermal release of hole from V-centers, and the recombination of there holes with electrons in F centers produces F^+ centers in an excited state and the de-excitation of the F^+ centers in turn produces 310nm radiation. In addition 310nm radiation, However, the 385K TSL peak contains 410nm emission band.
The 425K-TSL peaks are atributed to the thermal release of trapped electrons which is recaptured by existing F^+ centers there by converting them to excited state F centers which then relaxe to the ground state and produce 410nm radiation.
A close correlation between the 450K TSEE peak and the 425K TSL peak is observed. 450K TSEE peak can be considered as result of the energy transfer caused by an Auger-like mechanism between the electron in F center and the thermally released hole.