Artículos de revistas
Improved Conductivity Induced by Photodesorption in SnO2 Thin Films Grown by a Sol-Gel Dip Coating Technique
Fecha
1999-12-01Registro en:
Journal of Sol-Gel Science and Technology, v. 13, n. 1-3, p. 793-798, 1999.
0928-0707
10.1023/A:1008634131282
WOS:000078468200140
2-s2.0-0032312616
7730719476451232
5584298681870865
0000-0001-5762-6424
0000-0002-8356-8093
Autor
Universidade Estadual Paulista (Unesp)
Universidade de São Paulo (USP)
Institución
Resumen
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.