The excitation process of rare-earth ions in oxide semiconductors for optical emission is thought to be related to defect levels within the band-gap of the host material. In order to improve understanding of the role ...The excitation process of rare-earth ions in oxide semiconductors for optical emission is thought to be related to defect levels within the band-gap of the host material. In order to improve understanding of the role defect levels play in the energy transfer process, junction spectroscopy techniques can be used to investigate the electrically active emission centres. It has been reported that TiO<sub>2</sub> is sensitive to humidity at low temperatures, such as those employed when conducting junction spectroscopy measurements. However, there are not many discussions how to prevent this effect and to improve the quality of measurements. After optimization of samples such as fabrication of flat surface and encupsulant for preventing external effect, temperature dependent-capacitance measurements (C-T) were carried out to characterise shallow traps formed within TiO<sub>2</sub> band-gap. TiO<sub>2</sub> and Sm-doped TiO<sub>2</sub> thin films were deposited on SrTiO<sub>3</sub> (100) templates by laser ablaton and rectifying Ruthenium Oxide Schottky diodes deposited on the TiO<sub>2</sub> surface by laser ablation. A Sm or Sm-related shallow trap was observed in the Arrhenius plot of TiO<sub>2</sub>:Sm. In this paper, we show the optimized sample fabrication/preparation process that stabilizes the junction spectroscopy measurements, even in the presence of humidity and we present initial results obtained on samples using these optimized processing techniques.展开更多
The luminescence intensity of rare-earth ion-doped luminescent materials is closely related to the configuration of the anions around the rare-earth ions added to the host material and the lattice defects. And it is e...The luminescence intensity of rare-earth ion-doped luminescent materials is closely related to the configuration of the anions around the rare-earth ions added to the host material and the lattice defects. And it is expected that this information will be reflected in the XRD pattern. In this study, the lumines-cence data and XRD patterns of Sm-doped TiO<sub>2</sub> accumulated by our group are used to construct a model to predict the integrated luminescence intensity. The model was confirmed to be able to predict the integrated luminescence in-tensity with high accuracy. Furthermore, we found that the integrated lumi-nescence intensity of this system is closely related to the change in the position of the peak on the (200) plane of TiO<sub>2</sub>.展开更多
文摘The excitation process of rare-earth ions in oxide semiconductors for optical emission is thought to be related to defect levels within the band-gap of the host material. In order to improve understanding of the role defect levels play in the energy transfer process, junction spectroscopy techniques can be used to investigate the electrically active emission centres. It has been reported that TiO<sub>2</sub> is sensitive to humidity at low temperatures, such as those employed when conducting junction spectroscopy measurements. However, there are not many discussions how to prevent this effect and to improve the quality of measurements. After optimization of samples such as fabrication of flat surface and encupsulant for preventing external effect, temperature dependent-capacitance measurements (C-T) were carried out to characterise shallow traps formed within TiO<sub>2</sub> band-gap. TiO<sub>2</sub> and Sm-doped TiO<sub>2</sub> thin films were deposited on SrTiO<sub>3</sub> (100) templates by laser ablaton and rectifying Ruthenium Oxide Schottky diodes deposited on the TiO<sub>2</sub> surface by laser ablation. A Sm or Sm-related shallow trap was observed in the Arrhenius plot of TiO<sub>2</sub>:Sm. In this paper, we show the optimized sample fabrication/preparation process that stabilizes the junction spectroscopy measurements, even in the presence of humidity and we present initial results obtained on samples using these optimized processing techniques.
文摘The luminescence intensity of rare-earth ion-doped luminescent materials is closely related to the configuration of the anions around the rare-earth ions added to the host material and the lattice defects. And it is expected that this information will be reflected in the XRD pattern. In this study, the lumines-cence data and XRD patterns of Sm-doped TiO<sub>2</sub> accumulated by our group are used to construct a model to predict the integrated luminescence intensity. The model was confirmed to be able to predict the integrated luminescence in-tensity with high accuracy. Furthermore, we found that the integrated lumi-nescence intensity of this system is closely related to the change in the position of the peak on the (200) plane of TiO<sub>2</sub>.
