Preparation of TiO sub(2)/SnO sub(2) Thin Films by Sol-Gel Method and Periodic B3LYP Simulations

Titanium dioxide (TiO sub(2)) thin films are grown by the sol-gel dip-coating technique, in conjunction with SnO sub(2) in the form of a heterostructure. It was found that the crystalline structure of the most internal layer (TiO sub(2)) depends on the thermal annealing temperature and the substrate...

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Bibliographic Details
Published in:The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2014-08, Vol.118 (31), p.5857-5865-5857-5865
Main Authors: Floriano, Emerson A, Scalvi, Luis VA, Saeki, Margarida J, Sambrano, Julio R
Format: Article
Language:English
Subjects:
Annealing
Computing time
Heterostructures
Rutile
Semiconductors
Sol-gel processes
Thin films
Tin dioxide
Tin oxides
Titanium dioxide
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Summary:Titanium dioxide (TiO sub(2)) thin films are grown by the sol-gel dip-coating technique, in conjunction with SnO sub(2) in the form of a heterostructure. It was found that the crystalline structure of the most internal layer (TiO sub(2)) depends on the thermal annealing temperature and the substrate type. Films deposited on glass substrate submitted to thermal annealing until 550 degree C present anatase structure, whereas films deposited on quartz substrate transform to rutile structure at much higher temperatures, close to 1000 degree C, unlike powder samples where the phase transition takes place at about 780 degree C. When structured as rutile, the oxide semiconductors TiO sub(2)/SnO sub(2) have very close lattice parameters, making the heterostructure assembling easier. The SnO sub(2) and TiO sub(2) have their electronic properties evaluated by first-principles calculations by means of DFT/B3LYP. Taking into account the calculated band structure diagram of these materials, the TiO sub(2)/SnO sub(2) heterostructure is qualitatively investigated and proposed to increase the detection efficiency as gas sensors. This efficiency can be further improved by doping the SnO sub(2) layer with Sb atoms. This assembly may be also useful in photoelectrocatalysis processes.
ISSN:1089-5639
1520-5215
DOI:10.1021/jp411764t