[A study of photoluminescence properties of Si-based CeO2/Tb4O7 superlattices]

CeO2/Tb4O7 superlattices were deposited on P type Si wafers by e-beam evaporation technology. Four typical photoluminescence peaks of Tb3+ ions which located around 488, 544, 588 and 623 nm were obtained after the superlattices annealing in weak reducing atmosphere at high temperature. It was indicated that CeO2 films transferred to amorphous state as the valence transition of Ce4+ --> Ce3+ which was induced by thermal annealing, the energy transfer occurred between Ce3+ ions and Tb3+ ions, and the Tb3+ ions emition could be detected after obtaining the energy from Ce3+ ions. A study about the effect of Tb4O7 thickness on the superlattices photoluminescence showed that the maximum PL intensity as thickness of Tb4 O7 films were about 0.5 nm, the concentration quenching might occur because of the energy transfer among the Tb3+ ions. The annealing conditions research demonstrated that the maximum PL intensity could be obtained as the superlattices annealed at 1 200 degrees C for 2 hour. Further investigation inferred that the concentration of Ce3+ ions, Oxygen vacancy defects and the distance between Ce3+ ions and Tb3+ ions play an important role in the annealing process.