Electrical and spectroscopic analysis in nanostructured SnO2: "long-term" resistance drift is due to in-diffusion

A model for conductance in n-type non-degenerate semiconductors is proposed and applied to polycrystalline SnO2 used as a gas sensor. Particular attention is devoted to the fundamental mechanism of Schottky barrier formation due to surface states in nanostructured grains. Electrical and absorption i...

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Bibliographic Details
Authors: Malagù, Cesare, Giberti, Alessio, Morandi, Sara, Aldao, Celso Manuel
Format: article
Status:Published version
Publication Date:2011
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/10312
Online Access:http://hdl.handle.net/11336/10312
Access Level:Open access
Keyword:NANOESTRUCTURE TIN OXIDE
METAL OXIDE SENSORS
VACANCIES
SURFACE STATES
TUNNELING
CONDUCTION BANDS
FOURIER TRANSFORM INFRARED SPECTROSCOPY
https://purl.org/becyt/ford/2.5
https://purl.org/becyt/ford/2
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Description
Summary:A model for conductance in n-type non-degenerate semiconductors is proposed and applied to polycrystalline SnO2 used as a gas sensor. Particular attention is devoted to the fundamental mechanism of Schottky barrier formation due to surface states in nanostructured grains. Electrical and absorption infra-red spectroscopic analysis constitutes strong evidence for oxygen diffusion into the tin oxide grains. The model is then extended to include oxygen in- and out-diffusion. Thus, it is possible to explain the “long-term” resistance drift in oxygen for fully depleted grained samples in terms of tunneling through the double barrier.