Unraveling the Role of Sn Segregation in the Electronic Transport of Polycrystalline Hematite: Raising the Electronic Conductivity by Lowering the Grain-Boundary Blocking Effect

Autor(es)

Soares, Mario R. S. ^[1] ; Costa, Carlos A. R. ^[2] ; Lanzoni, Evandro M. ^[2] ; Bettini, Jefferson ^[2] ; Ramirez, Carlos A. O. ^[2] ; Souza, Flavio L. ^[3] ; Longo, Elson ^[1] ; Leite, Edson R. ^{[2, 1]}

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Chem Dept, BR-13565905 Sao Carlos, SP - Brazil

^[2] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas, SP - Brazil

^[3] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ADVANCED ELECTRONIC MATERIALS; v. 5, n. 6 JUN 2019.
• Citações Web of Science: 0

Resumo

This paper describes the role of SnO2 in the electronic transport of polycrystalline hematite (alpha-Fe2O3). The proper sintering process allows for freezing of a state of electronic defects, in which the electrical properties of hematite are controlled by the grain boundary and Sn segregation. Impedance spectroscopy and dc conductivity measurements show that current flows through preferential pathways associated with Sn segregation that occurs at the grain boundary, leading to a decrease in grain-boundary resistance. Atomic force microscopy and electric force microscopy measurements confirm the results of the impedance analysis. The identification of preferential grain boundaries for electrical conductivity may have a direct influence on the light-induced water-splitting performance of the hematite photoanode. (AU)

• Processo FAPESP: 17/03135-5 - Contornos de grãos em materiais eletro-cerâmicos: compreendendo a natureza e sua função na hematita (Fe2O3)
• Beneficiário: Edson Roberto Leite
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
• Beneficiário: Adalberto Fazzio
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• 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