Charge storage in oxygen deficient phases of TiO2: defect Physics without defects
Carregando...
Arquivos
Data
2016-07-01
Autores
Padilha, A. C. M.
Raebiger, H.
Rocha, A. R. [UNESP]
Dalpian, G. M.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Nature Publishing Group
Resumo
Defects in semiconductors can exhibit multiple charge states, which can be used for charge storage applications. Here we consider such charge storage in a series of oxygen deficient phases of TiO2, known as Magneli phases. These Magneli phases (TinO2n-1) present well-defined crystalline structures, i.e., their deviation from stoichiometry is accommodated by changes in space group as opposed to point defects. We show that these phases exhibit intermediate bands with an electronic quadruple donor transitions akin to interstitial Ti defect levels in rutile TiO2. Thus, the Magneli phases behave as if they contained a very large pseudo-defect density: 1/2 per formula unit TinO2n-1. Depending on the Fermi Energy the whole material will become charged. These crystals are natural charge storage materials with a storage capacity that rivals the best known supercapacitors.
Descrição
Palavras-chave
Como citar
Scientific Reports. London: Nature Publishing Group, v. 6, 7 p., 2016.