Nanosized Thin SnO2 Layers Doped with Te and TeO2 as Room Temperature Humidity Sensors

Sensors

Biliana Georgieva¹  Irena Podolesheva²  Georgy Spasov² 

[1] Institute of Optical Materials and Technologies “Acad. J. Malinowski”, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl.109, Sofia 1113, Bulgaria;

关键词: SnO₂;    humidity sensors;    thin layers;    room temperature sensing;   

DOI  :  10.3390/s140508950

来源: mdpi

【 摘 要 】

In this paper the humidity sensing properties of layers prepared by a new method for obtaining doped tin oxide are studied. Different techniques—SEM, EDS in SEM, TEM, SAED, AES and electrical measurements—are used for detailed characterization of the thin layers. The as-deposited layers are amorphous with great specific area and low density. They are built up of a fine grained matrix, consisting of Sn- and Te-oxides, and a nanosized dispersed phase of Te, Sn and/or SnTe. The chemical composition of both the matrix and the nanosized particles depends on the ratio R_Sn/Te and the evaporation conditions. It is shown that as-deposited layers with R_Sn/Te ranging from 0.4 to 0.9 exhibit excellent characteristics as humidity sensors operating at room temperature—very high sensitivity, good selectivity, fast response and short recovery period. Ageing tests have shown that the layers possess good long-term stability. Results obtained regarding the type of the water adsorption on the layers' surface help better understand the relation between preparation conditions, structure, composition and humidity sensing properties.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.