Transient Absorption Spectroscopy of TlBr Crystals Using Pulsed Electron Beams.

We analyzed the transient absorption properties of TlBr crystals using pulsed electron beams as excitation sources. We observed transient absorption spectra and temporal profiles on the pico- and nanosecond scales and compared the results obtained for TIBr crystals that are empirically appropriate with those that are inappropriate for semiconductor detectors. The results showed negligible differences in properties between the two types of crystal, which indicates that their trap center concentrations were similar. A transient absorption band was observed at approximately 1160 nm on the nanosecond scale, while its short-wavelength tail was observed on the picosecond scale. The absorption band is attributed to the localized holes at Tl+ that are stabilized by some defects. In contrast, no absorption band attributable to localized electron centers was observed, indicating that while hole transport is hindered by defects, electron transport is not [ABSTRACT FROM AUTHOR]