Photo-induced electrical behavior under gas adsorption on SnO2 -based heterostructures
| Autor: | Fabricio Trombini Russo, Diego H. O. Machado, Luis Vicente de Andrade Scalvi, José Humberto Dias da Silva |
|---|---|
| Přispěvatelé: | Universidade Estadual Paulista (Unesp) |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
business.industry Band gap Heterojunction 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Evaporation (deposition) 0104 chemical sciences Crystal Tin dioxide Electrical transport Gallium arsenide Adsorption Sputtering Heterostructure Optoelectronics General Materials Science Wafer Thin film 0210 nano-technology business Gas sensing |
| Zdroj: | Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP |
| ISSN: | 0254-0584 |
| Popis: | Made available in DSpace on 2020-12-12T01:32:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Er-doped SnO2 thin films are produced by a combined technique where films are deposited by resistive evaporation from a precursor powder obtained by sol-gel. Films are deposited on different substrates and analyzed concerning the electrical conduction on different directions. The film conductivity (parallel to the surface) changed significantly when exposed to light, even though the photon energies are below the SnO2 bandgap energy (InGaN LED, 2.75 eV). The SnO2 films present distinct trapping characteristics when exposed to oxygen or carbon monoxide, in agreement with the behavior of metallic oxides, suggesting that surface defects act as adsorption sites. The photo-excitation is rather lower for a GaAs/SnO2 heterostructure sample where the GaAs layer is deposited by sputtering, since the direction of polarization (through the interface barrier, perpendicular to the sample surface) does not lead to significant increase in the sample current. When the bottom layer is a GaAs crystal wafer, the current magnitude increases drastically under the InGaN LED excitation. The results reported here contribute to the understanding of electrical transport and the influence of gas adsorption on evaporated SnO2 films deposited in diverse configurations on distinct substrates, and contributes to gas sensing applications. UNESP São Paulo State University Department of Physics FC and Graduate Program in Materials Science and Technology (POSMAT) UNESP São Paulo State University Department of Physics FC and Graduate Program in Materials Science and Technology (POSMAT) FAPESP: 2016/12216-6 FAPESP: 2017/18916-2 |
| Databáze: | OpenAIRE |
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