Conductivity in SnO2 polycrystalline thick film gas sensors: Tunneling electron transport and oxygen diffusion

SENSORS AND ACTUATORS B-CHEMICAL

卷:193

Article

Aldao, C. M.^1,2  Schipani, F.^1,2  Ponce, M. A.^1,2  Joanni, E.³  Williams, F. J.^4,5,6 

[1] Univ Mar del Plata, Inst Mat Sci & Technol, INTEMA, Mar Del Plata, Buenos Aires, Argentina

[2] Consejo Nacl Invest Cient & Tecn, Natl Res Council, Mar Del Plata, Buenos Aires, Argentina

[3] CTI Renato Archer, BR-13069901 Campinas, SP, Brazil

[4] Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Quim Inorgan Analit & Quim Fis, Buenos Aires, DF, Argentina

[5] Univ Buenos Aires, Fac Ciencias Exactas & Nat, INQUIMAE, Buenos Aires, DF, Argentina

[6] Consejo Nacl Invest Cient & Tecn, Buenos Aires, DF, Argentina

关键词: SnO2;    Electron tunneling;    Oxygen diffusion;   

DOI  :  10.1016/j.snb.2013.11.114

来源: Elsevier

【 摘 要 】

Conduction mechanisms in polycrystalline SnO2 thick sensing films were investigated by means of DC electrical resistance during heating-cooling cycles. Samples were maintained at relatively high temperatures in H-2 or O-2 ambient atmospheres before performing electrical measurements under vacuum or before performing XPS measurements in order to determine band bending. Results suggest that inter-grains present Schottky barriers that are responsible for the observed conductivities regardless of gas pre-treatment. Oxygen diffusion modulates barrier widths affecting conductivity through tunneling transport. The electrical response to subsequent exposure to an oxygen atmosphere is consistent with our interpretation. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

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