SELENIUM MOLECULES AND THEIR POSSIBLE ROLE IN DEEP EMISSION FROM GLASSES DOPED WITH SELENIDE NANOCRYSTALS

We report the observation of Raman scattering from a vibration mode wi th frequency of 320 cm(-1) and its higher-order harmonics in silicate glasses doped with selenide semiconductor nanocrystals such as CdSe an d ZnSe. Comparison with Raman spectra of glasses and alkali halides do ped with Se suggests that these modes are caused by the presence or se lenium molecules in the glasses; When excited in the blue and. green b y an Ar+ laser, glasses containing Se only are found to emit strong ne ar-infrared luminescence whose peak and Line shape are very similar to the so-called ''deep emission'' observed frequently from selenide-dop ed glasses. Possible effects of Se molecules on the linear and nonline ar optical properties of glasses containing selenide nanocrystals are discussed. (C) 1996 American Institute of Physics.