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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Anatase-Rutile Transition and Photo-Induced Conductivity of Highly Yb-Doped TiO(2)Films Deposited by Acid Sol-Gel Dip-Coating Method

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Pedrini, Luiz F. Kaezmarek [1, 2] ; Santos, Stevan B. O. [1, 2] ; Trino, Luciana D. [3] ; Scalvi, Luis V. A. [1, 2]
Total Authors: 4
[1] Sao Paulo State Univ UNESP, Dept Phys, FC, Bauru, SP - Brazil
[2] Sao Paulo State Univ UNESP, POSMAT Postgrad Program Mat Sci & Technol, Bauru, SP - Brazil
[3] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biosci Natl Lab LNBio, Campinas, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Web of Science Citations: 0

A method to prepare Yb-doped TiO(2)is proposed, using titanium isopropoxide and ytterbium oxide. Thin films and powders are produced through the sol-gel technique where the Yb concentrations are 0.01 at.%, 0.02 at.%, 1 at.%, 2 at.% 4 at.% and 8 at.%. The increase in the doping concentration intensifies gradually the sample transparency for the whole observed spectrum and reaches the transparency degree of the undoped sample with the highest concentration of ytterbium. By means of x-ray diffraction (XRD) we find that the solution's pH leads to the formation of a rutile structure which is compensated for by lanthanide doping, inhibiting the anatase-rutile phase transformation. Then, the XRD profile depends on the Yb concentration, being mostly anatase for undoped and highly (8 at.%) doped samples, with mixed ratios of these two phases in other concentrations. Maintaining an acid solution leads to fewer intergrain defects in the rutile structure contributing to higher conductivity. Photo-induced investigation of 8 at.% Yb-doped thin film, using several light sources leads to distinct behavior concerning the excitation of intra-bandgap states and/or electron-hole pairs. This result helps to understand the electronic transport in Yb-doped TiO(2)and shows that devices based on its conductivity may have improved performance by irradiation with controlled light energy. (AU)

FAPESP's process: 19/00683-7 - Deposition of heterostrucures of SnO2 and TiO2 by dip-coating using a two phase technique
Grantee:Luiz Felipe Kaezmarek Pedrini
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 18/25241-4 - Investigation of structural, electrical and optical properties of the hybrid structure PbxSn1-xO2/TiO2: interface analysis and influence of substrate temperature
Grantee:Stevan Brayan Oliveira dos Santos
Support Opportunities: Scholarships in Brazil - Master