Low-temperature luminescence of ScF3 single crystals under excitation by VUV synchrotron radiation

Photoluminescence and excitation spectra of ScF3 single crystals have been measured under vacuum ultraviolet excitations utilizing undulator synchrotron radiation from 1.5 GeV storage ring of MAX IV synchrotron. The emission peak at 280 nm is explained as emission band of self-trapped excitons in ScF3. This emission is quenched at 50 K and activation energy of thermal quenching was obtained. The excitation spectrum in vacuum ultraviolet spectral range exhibits that the luminescence of self-trapped excitons effectively occurs under direct excitation in the excitonic absorption band, whereas under higher energies this excitation is strongly suppressed, however, multiplication of electronic excitation processes have been successfully identified.