Anomalous anisotropic exciton temperature dependence in rutile TiO2
نویسندگان
چکیده
Edoardo Baldini,1,* Adriel Dominguez,2 Letizia Chiodo,3 Evgeniia Sheveleva,4 Meghdad Yazdi-Rizi,4 Christian Bernhard,4 Angel Rubio,2,5 and Majed Chergui1 1Laboratory of Ultrafast Spectroscopy, ISIC and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland 2Max Planck Institute for the Structure and Dynamics of Matter, D-22761 Hamburg, Germany 3Unit of Nonlinear Physics and Mathematical Modeling, Department of Engineering, Università Campus Bio-Medico di Roma, Via Álvaro del Portillo 21, I-00128, Rome, Italy 4Department of Physics, University of Fribourg, Chemin du Musée 3, CH-1700 Fribourg, Switzerland 5Departamento Física de Materiales, Universidad del País Vasco, Avenida Tolosa 72, E-20018 San Sebastián, Spain (Received 3 April 2017; published 19 July 2017)
منابع مشابه
Room Temperature Synthesis of N-doped Urchin-like Rutile TiO2 Nanostructure With Enhanced Photocatalytic Activity Under Sunlight
We report the synthesis of nitrogen-doped urchin-like rutile TiO2 nanostructure at room temperature without further heat treatment. The process was operated through hydrolysis of Ti(OC4H9)4 employing the direct amination of the product. The samples characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Raman spectroscopy and Brunaue...
متن کاملWhy is anatase a better photocatalyst than rutile? - Model studies on epitaxial TiO2 films
The prototypical photocatalyst TiO2 exists in different polymorphs, the most common forms are the anatase- and rutile-crystal structures. Generally, anatase is more active than rutile, but no consensus exists to explain this difference. Here we demonstrate that it is the bulk transport of excitons to the surface that contributes to the difference. Utilizing high -quality epitaxial TiO2 films of...
متن کاملEffect of Annealing Temperature on Structural, Electrical and Optical Properties of TiO2 Nanopowder
TiO2 nanopowder is prepared by simple sol-gel method using starting material as titanium isopropoxide with methanol and annealed at 600°C, 700°C and 800°C for 1 hour in air. X-ray diffraction pattern revealed the presence of both anatase and rutile phase in TiO2 specimens annealed at different temperatures. It is observed that the content of rutile phase and crystallite size increases with incr...
متن کاملOrientation Dependence of Photochemical Reactions on TiO2 Surfaces
The photochemistry of oriented rutile surfaces has been examined using the photoreduction of Ag+ to Ag metal from an aqueous solution onto the TiO2 surfaces. The photochemical reaction rates and quantum yields of rutile films were found to be a function of the orientation of the rutile surface. The (100) and (110) rutile orientations have lower photoreduction rates than the (101), (111), and (0...
متن کاملOrigin of anomalous temperature dependence and high efficiency of silicon light-emitting diodes
Efficient electroluminescence with power efficiency up to 0.12% is observed from silicon pn diodes prepared by boron implantation with boron concentrations above the solubility limit at the postimplantation annealing temperature. The electroluminescence spectra exhibit a transition from two bound-exciton bands towards the free electron-hole pair recombination with an anomalous increase in the t...
متن کامل