Title:	Uso do Modelo de Holstein-Peierls para o estudo do transporte de carga em cristais de pentatienoaceno
Authors:	Torres, Rayane Tayná da Costa
Orientador(es)::	Ribeiro Júnior, Luiz Antônio
Assunto::	Pentatienoaceno Transporte de carga Pólaron Modelo Holstein-Peierls
Issue Date:	28-Oct-2021
Data de defesa::	20-Aug-2021
Citation:	TORRES, Rayane Tayná da Costa. Uso do Modelo de Holstein-Peierls para o estudo do transporte de carga em cristais de pentatienoaceno. 2021. 63 f., il. Dissertação (Mestrado em Ciências de Materiais) – Universidade de Brasília, Brasília, 2021.
Abstract:	The pentathienoacene molecular crystal is a good organic semiconductor in terms of charge transport, therefore a promising material for organic electronics. The so -called organic electronics brings new perspectives to technology by inserting in the scientific world the organic semiconductors, materials characterized by being recyclable, lightweight, cheap, relying on abundant resources, and of superior efficiency to inorganic devices. The most prominent optoelectronic devices for organic electronics are organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs). Organic molecular crystals are semiconductors of great relevance, because they are materials with unique characteristics such as compressibility and flexibility. Among the molecular crystals, pentathienoacene (5TA or PTA) stands out for its well- defined crystal structure and good stability. Despite their excellent structural versatility, organic semiconductors have complex electron movement. Therefore, charge transport is considered one of the most important characteristics to be improved in order to improve the performance of the devices. Responsible for characterizing the charge transport in organic semiconductors are the polarons: collective excitations that cause lattice deformation in the presence of charge. Since molecular crystals have intramolecular and intermolecular degrees of freedom, the model suitable for analyzing charge transport is called Holstein-Peierls, this model takes into account the influence of local and non-local electron-phonon couplings. An in-depth analysis of the stationary and dynamic properties of charge carriers in 5TA is lacking in the literature, even though it is of great importance for the development of electronics. The objective of this work is to study charge transport in 5TA molecular crystals, taking into account the influence of intramolecular and intermolecular electron-phonon couplings, using the Holstein-Peierls semiclassical model. In relation to the results, the parameters played an important role, because through them arises the possibility of forming stable quasi-particles (polarons) in the system. The stability of the polaron, measured here by the formation energy, is within the expected values for semiconductors. The parametric region of interest found in PTA crystals is the one that produces the stably extended polaron. Regarding dynamics, the movement of the polaron can occur for an electric field threshold that exceeds the standard value for organic crystalline semiconductors. Furthermore, the results show that charge transport is essentially one- dimensional in 5TA crystals.
metadata.dc.description.unidade:	Faculdade UnB Planaltina (FUP)
Description:	Dissertação (mestrado) – Universidade de Brasília, Faculdade UnB de Planaltina, Programa de Pós-Graduação em Ciências de Materiais, 2021.
metadata.dc.description.ppg:	Programa de Pós-Graduação em Ciências de Materiais
Licença::	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Appears in Collections:	Teses, dissertações e produtos pós-doutorado

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