Effects of donor density on power-law response in tin dioxide gas sensors

Autor(es)

Mirabella, D. A. ^{[1, 2]} ; Desimone, P. M. ^{[1, 2]} ; Ponce, M. A. ^{[1, 2]} ; Aldao, C. M. ^{[1, 2]} ; da Silva, L. F. ^[3] ; Catto, A. C. ^[3] ; Longo, E. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Mar Del Plata, Inst Mat Sci & Technol INTEMA, Juan B Justo 4302, B7608FDQ, Mar Del Plata - Argentina

^[2] Natl Res Council CONICET, Juan B Justo 4302, B7608FDQ, Mar Del Plata - Argentina

^[3] Univ Fed Sao Carlos, Dept Phys, Lab Nanostruct Multifunct Mat, BR-13565905 Sao Carlos, SP - Brazil

^[4] Fed Univ Sao Carlos UFSCar, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SENSORS AND ACTUATORS B-CHEMICAL; v. 329, FEB 15 2021.
• Citações Web of Science: 1

Resumo

We investigated the power-law responses in two types of tin dioxide (SnO2) films: one made from nanosized grains and another from from very large grains, both under dry air. Experimental results revealed a significant dependence between the sensitivity and the SnO2 grain size. We therefore propose, that the gas sensor sensitivity is not only determined by oxygen chemisorption, but also by changes in the density of oxygen vacancies in response to changes in the ambient gas pressure. Band bendings and adsorbate coverages for different oxygen pressures were derived resorting to the electroneutrality condition, including changes in the concentration of oxygen vacancies within the grains due to the exposure to different oxygen pressure. The consequences for the film conductivity and its power-law response were analyzed and compared with experimental results. (AU)

• Processo FAPESP: 18/18208-0 - Heteroestruturas a-Fe2O3/g-C3N4: Preparação, Caracterização e Aplicação como Sensores Resistivos de Gás
• Beneficiário: Ariadne Cristina Catto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 17/12437-5 - Preparação e caracterização de nanoheterojunções semicondutoras aplicadas como sensores resistivos de gás fotoativados
• Beneficiário: Luís Fernando da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular