Improved Conductivity Induced by Photodesorption in SnO2 Thin Films Grown by a Sol-Gel Dip Coating Technique
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Data
1999-12-01
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Coorientador
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Curso de graduação
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Resumo
Thin films of undoped and Sb-doped SnO2 have been prepared by a sol-gel dip-coating technique. For the high doping level (2-3 mol% Sb) n-type degenerate conduction is expected, however, measurements of resistance as a function of temperature show that doped samples exhibit strong electron trapping, with capture levels at 39 and 81 meV. Heating in a vacuum and irradiation with UV monochromatic light (305 nm) improve the electrical characteristics, decreasing the carrier capture at low temperature. This suggests an oxygen related level, which can be eliminated by a photodesorption process. Absorption spectral dependence indicates an indirect bandgap transition with Eg ≅ 3.5 eV. Current-voltage characteristics indicate a thermionic emission mechanism through interfacial states.
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Electronic transport, Impurities in semiconductors, Recombination and trapping, Thin films, Charge carriers, Current voltage characteristics, Desorption, Electric resistance measurement, Electron transport properties, Energy gap, Semiconducting antimony, Semiconducting tin compounds, Semiconductor doping, Sol-gels, Thermal effects, Ultraviolet radiation, Absorption spectroscopy, Approximation theory, Coating techniques, Monochromators, Semiconductor materials, Single crystals, Dip coating, Photodesorption, Photodesorption process, Semiconducting films, Tin compounds
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Inglês
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Journal of Sol-Gel Science and Technology, v. 13, n. 1-3, p. 793-798, 1999.
