| Texto completo | |
| Autor(es): |
Pozzoli, Guilherme L.
[1, 2]
;
Merces, Leandro
[1]
;
Yassitepe, Emre
[1, 3]
;
de Morais, Vitoria B.
[1]
;
de Camargo, Davi H. S.
[1, 2]
;
Bufon, Carlos C. Bof
[1, 2]
Número total de Autores: 6
|
| Afiliação do(s) autor(es): | [1] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas, SP - Brazil
[2] Sao Paulo State Univ UNESP, Postgrad Program Mat Sci & Technol POSMAT, BR-17033360 Bauru, SP - Brazil
[3] Fed Univ Maranhao UFMA, Dept Phys CCET, BR-65080805 Sao Luis, Maranhao - Brazil
Número total de Afiliações: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ACS APPLIED NANO MATERIALS; v. 3, n. 3, p. 3060-3070, MAR 2020. |
| Citações Web of Science: | 0 |
| Resumo | |
The investigation of the charge-transport mechanism across disordered conducting and semiconducting materials is of relevance, considering the applications in modern organic and hybrid electronics. The transition from bulk to nm-thick layers may lead to unexpected physical/chemical properties as the device interfaces do influence the overall charge-carrier conduction. Here, we present an investigation of the electrical transport across vertical heterojunctions having disordered nm-thick films (polypyrrole, PPy) as the active material. The PPy structures are prepared by chemical polymerization from the pyrrole vapor phase, resulting in film thicknesses of a few tens of nanometers. The electrical characteristics of the devices are evaluated as a function of voltage and temperature, and the charge transport is found to be strongly influenced by the presence of trap states at the PPy highest occupied molecular orbital-giving rise to space-chargelimited conduction with exponential distribution of traps. The trapping-state density is calculated, and X-ray photoelectron spectroscopy revealed an increase of disorder and a reduced doping density at the PPy growth interface. As a proof of concept, the PPy films integrated within the as-fabricated vertical heterostructures are applied as photosensitive devices. The observation of photocurrent is correlated to the presence of a gradient in the doping profile (from ca. 27.6 to 17.2% when thickness decreases from 120 to 20 nm). Our findings contribute to the elucidation of the charge-trapping center's origin in the nm-thick PPy films, as well as envision further applications in photoelectrochemistry, solar cells, and water splitting. (AU) | |
| Processo FAPESP: | 18/18136-0 - Nanodispositivos híbridos: transporte magnetoeletrônico e desenvolvimento de sensores baseados em moléculas/nanomembranas |
| Beneficiário: | Leandro das Mercês Silva |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 14/25979-2 - Fabricação e caracterização de dispositivos e sistemas baseados em nanomembranas híbridas |
| Beneficiário: | Carlos César Bof Bufon |
| Modalidade de apoio: | Auxílio à Pesquisa - Jovens Pesquisadores |
| Processo FAPESP: | 14/50906-9 - INCT 2014: em Materiais Complexos Funcionais (INOMAT) |
| Beneficiário: | Fernando Galembeck |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |