Structural and Photoluminescence Properties of Evaporated SnO2 Thin Films Doped with Rare Earths

The structure and the luminescence properties of neodymium- and terbium-doped SnO2 thin films were investigated by using x-ray diffraction and electron microscopy, infrared absorption, Raman and photoluminescence (PL) spectroscopies. The films were obtained by evaporation of SnO2 and rare earths (RE) on silicon substrates maintained at 100 °C. The as-deposited films were sub-stoichiometric and the films were then annealed in air at different temperatures. The structural characterization shows that the rutile phase is obtained for annealing temperatures greater than 600 °C. In this phase, photoluminescence experiments show that the rare-earth ions are optically activated.