ArticleAuthors: Trinh, Thi Loan; Nguyen, Ngoc Long (2014)
Anatase TiO2 powders doped with 0.5, 1.0, 4.0 and 10 mol% Cr3+ have been prepared by hydrothermal method. The Cr3+ concentration and annealing effects on crystalline structure, absorption and photoluminescent spectra of the synthesized samples have been investigated. The band gap energy of anatase and rutile TiO2:Cr3+ powders with different dopant contents has been determined. Urbach energies (Eu) characterized for the structural disorder in the anatase and rutile TiO2 host lattice doped with Cr3+ ions also have been calculated with different impurity concentrations. At low annealing temperature (≤ 600 oC), the samples exhibited anatase phase and the photoluminescent spectra consisted...