Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1021/acsanm.0c00523 http://hdl.handle.net/11449/198661 |
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-charge-limited 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. |
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Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generationgradient dopingheterojunctionnanoelectronicsnanomembranephotocurrentpolymerThe 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-charge-limited 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.Brazilian Nanotechnology National Laboratory (LNNano) Brazilian Center for Research in Energy and Materials (CNPEM)Postgraduate Program in Materials Science and Technology (POSMAT) Saõ Paulo State University (UNESP)Department of Physics (CCET) Federal University of Maranhaõ (UFMA)Postgraduate Program in Materials Science and Technology (POSMAT) Saõ Paulo State University (UNESP)Brazilian Center for Research in Energy and Materials (CNPEM)Universidade Estadual Paulista (Unesp)Federal University of Maranhaõ (UFMA)Pozzoli, Guilherme L. [UNESP]Merces, LeandroYassitepe, EmreDe Morais, Vitória B.De Camargo, Davi H. S. [UNESP]Bufon, Carlos C. Bof [UNESP]2020-12-12T01:18:48Z2020-12-12T01:18:48Z2020-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1021/acsanm.0c00523ACS Applied Nano Materials.2574-0970http://hdl.handle.net/11449/19866110.1021/acsanm.0c005232-s2.0-85082180630Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengACS Applied Nano Materialsinfo:eu-repo/semantics/openAccess2021-10-22T18:27:14Zoai:repositorio.unesp.br:11449/198661Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:09:19.495275Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
title |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
spellingShingle |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation Pozzoli, Guilherme L. [UNESP] gradient doping heterojunction nanoelectronics nanomembrane photocurrent polymer |
title_short |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
title_full |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
title_fullStr |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
title_full_unstemmed |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
title_sort |
Charge Transport and Gradient Doping in Nanostructured Polypyrrole Films for Applications in Photocurrent Generation |
author |
Pozzoli, Guilherme L. [UNESP] |
author_facet |
Pozzoli, Guilherme L. [UNESP] Merces, Leandro Yassitepe, Emre De Morais, Vitória B. De Camargo, Davi H. S. [UNESP] Bufon, Carlos C. Bof [UNESP] |
author_role |
author |
author2 |
Merces, Leandro Yassitepe, Emre De Morais, Vitória B. De Camargo, Davi H. S. [UNESP] Bufon, Carlos C. Bof [UNESP] |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
Brazilian Center for Research in Energy and Materials (CNPEM) Universidade Estadual Paulista (Unesp) Federal University of Maranhaõ (UFMA) |
dc.contributor.author.fl_str_mv |
Pozzoli, Guilherme L. [UNESP] Merces, Leandro Yassitepe, Emre De Morais, Vitória B. De Camargo, Davi H. S. [UNESP] Bufon, Carlos C. Bof [UNESP] |
dc.subject.por.fl_str_mv |
gradient doping heterojunction nanoelectronics nanomembrane photocurrent polymer |
topic |
gradient doping heterojunction nanoelectronics nanomembrane photocurrent polymer |
description |
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-charge-limited 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. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-12-12T01:18:48Z 2020-12-12T01:18:48Z 2020-01-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1021/acsanm.0c00523 ACS Applied Nano Materials. 2574-0970 http://hdl.handle.net/11449/198661 10.1021/acsanm.0c00523 2-s2.0-85082180630 |
url |
http://dx.doi.org/10.1021/acsanm.0c00523 http://hdl.handle.net/11449/198661 |
identifier_str_mv |
ACS Applied Nano Materials. 2574-0970 10.1021/acsanm.0c00523 2-s2.0-85082180630 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
ACS Applied Nano Materials |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128469433843712 |