Investigation of sensing properties of sol–gel processed 4 at%Sb:SnO2/TiO2 thin films

• Autor(a) principal: Boratto, Miguel H. [UNESP]
• Data de Publicação: 2018
• Outros Autores: Ramos, Roberto A. [UNESP], Scalvi, Luis V. A. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1007/s10854-017-7935-x; http://hdl.handle.net/11449/170256

In this work we investigate the gas and photo sensing properties of the antimony doped tin oxide and titanium oxide (4 at%Sb:SnO2/TiO2) nanocrystalline thin films deposited by sol–gel dip-coating. Photoconductivity measurements are carried out under solar light spectra irradiation at different powers. These results show a photo sensitivity of the films in a lateral junction due to interfacial defects. Gas sensitivity was studied at different pressures, and higher conductivity is presented at lower pressure compared to oxygen-rich atmosphere. It occurs due to absence of oxygen adsorption on the semiconductors surface. TiO2 films are also investigated concerning its properties to gas sensing under photo-excitation with InGaN LED light source with wavelength centered in 450 nm. The decay of photo-induced current evaluated under O2 and vacuum atmospheres shows that the sample illumination may contribute to higher gas-sensitivity. This measurement allows determining the charge carrier capture energy, that is related to trapping dominated by distinct defects in each atmosphere.