Annealing effects on the structural and optical properties of vanadium oxide film obtained by the hot-filament metal oxide deposition technique (HFMOD)

Materia

Moraes, Mário Antonio Bica de¹  Scarminio, Jair²  Silva, Paulo Rogério Catarini da²  Gelamo, Rogério Valentim³ 

[1] Universidade Estadual de Campinas, Campinas, Brazil;Universidade Estadual de Londrina, Londrina, Brazil;Universidade Federal do Triângulo Mineiro, Uberaba, Brazil

关键词: vanadium oxide film;    HFMOD technique;    annealing;    crystalline structure;    optical absorption.;   

DOI  :  10.1590/s1517-707620170001.0113

学科分类：工程和技术（综合）

来源: Universidade Federal do Rio de Janeiro * Coordenacao dos Programas de Pos-Graduacao de Engenharia

【 摘 要 】

Vanadium oxide films amorphous, nonstoichiometric and highly absorbing in the optical region were deposited on ITO-coated glass and on silicon substrates, by the hot-filament metal oxide deposition technique (HFMOD) and oxidized by ex-situ annealing in a furnace at 200, 300, 400 and 500 ºC, under an atmosphere of argon and rarefied oxygen. X-ray diffraction, Raman and Rutherford backscattering spectroscopy as well as optical transmission were employed to characterize the amorphous and annealed films. When annealed at 200 and 300 ºC the as-deposited opaque films become transparent but still amorphous. Under treatments at 400 and 500 ºC a crystalline nonstoichiometric V2O5 structure is formed. All the annealed films became semiconducting, with their optical absorption coefficients changing with the annealing temperature. An optical gap of 2.25 eV was measured for the films annealed at 400 and 500 ºC. The annealing in rarefied oxygen atmosphere proved to be a useful and simple ex-situ method to modulate the structural and optical properties of vanadium oxide films deposited by HFMOD technique. This technique could be applied to other amorphous and non-absorbing oxide films, replacing the conventional and sometimes expensive method of modulate desirable film properties by controlling the film deposition parameters. Even more, the HFMOD technique can be an inexpensive alternative to deposit metal oxide films.

【 授权许可】

CC BY