Rare earth doped silica films were prepared by sol-gel method accompanied with the spin-coating process. It was found that the photoluminescence (PL) property of the thin films was dependent strongly on the doping amount of Eu3+. For thin films annealed at 700 ℃, the PL intensity increased constantly as elevating the doping amount up to 10% without any evident concentration quench, which indicated the good doping property of the SiO_2 matrix. In order to further improve the PL efficiency, co-doping of Tb3+ into SiO_2∶Eu3+ thin films were also investigated. It was found that the luminescence intensity was obviously enhanced by co-doping which could be explained in terms of the effective energy transfer from Tb3+ to Eu3+.
Intensive blue photoluminescence (PL) was observed at room temperature from the nanocrystalline-Si/SiO2 (nc-Si/SiO2 ) multilayers (MLs) obtained by thermal annealing of SiO/SiO2 MLs for the first time. By controlling the size of nc-Si formed in SiO sublayer from 3.5 to 1.5 nm, the PL peak blueshifts from 457 to 411 nm. Combining the analysis of TEM, Raman and absorption measurement, this paper attributes the blue PL to multiple luminescent centres at the interface of nc-Si and SiO2 .
