Transient optical absorption in berillium oxide crystals induced by an electron beam pulse has been studied by time-resolved absorption spectroscopy. The decay kinetics of this absorption reveals a component with a 6.5-ms time constant associated with the formation and decay of self-trapped holes. The absorption band of the self-trapped holes peaking at 3.6 eV and the UV absorption region of self-trapped excitons in BeO have been found to have similar properties. A model discussed is presenting the self-trapped hole as a small-radius polaron (of the O- ion-type) whose motion cannot be completely frozen out because of tunneling migration is discussed. At T> 100 K, thermally activated motion of self-trapped holes to electronic traps involving formation of self-trapped excitons is observed to occur.
|Журнал||Physics of the Solid State|
|Состояние||Опубликовано - янв 1996|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics