Low-temperature photoluminescence in SnO2 high-resistivity monocrystals

Stannic oxide monocrystals behave like photoluminescent emitters over the whole visible range. The emission spectra are measured for temperatures between 29 and 77 K. The shape and the width of emitted band components lead to an analyse of the data by the energy configuration–coordinate model. This quantum scheme is usually developed to describe the behaviour of colour centres in alkali-halides or phosphors. Two emission bands are selected and analysed in this way, leading to the evaluation of characteristic parameters for two complexes, the physical origin of which is likely the same because of the common vibrational structure of their excited state. Energetic schemes are included in the band gap of SnO2 and related to the band-to-band excitation and to photoconductivity. The physical nature of these centres is emphasized.