Anais do Workshop do INEO 2026

URBACH ENERGY: FILM PROCESSING AND THICKNESS EFFECTS

Publicado em 27/05/2026 - ISBN: 978-65-272-2467-9

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Trabalho
Título do Trabalho
URBACH ENERGY: FILM PROCESSING AND THICKNESS EFFECTS
Autores
  • Marleane Maria Felix de Azevedo
  • Endel Ezequiel Carvalho Costa
  • Guilherme Severino Mendes de Araújo
  • Kayla Manuelli Pimentel de Carvalho
  • Cleânio da Luz Lima; UFPI
  • Angel Alberto Hidalgo
  • Maria Leticia Vega
Modalidade
Pôster - resumo
Área temática
Dispositivos eletrônicos, eletroquímicos, supercapacitores e baterias
Data de Publicação
27/05/2026
País da Publicação
Brasil
Idioma da Publicação
pt-BR
Página do Trabalho
https://www.even3.com.br/anais/workshop-do-ineo-2026/1465066-urbach-energy--film-processing-and-thickness-effects
ISBN
978-65-272-2467-9
Palavras-Chave
Urbach energy, Langmuir-Blodgett, deep traps, shalow traps
Resumo
Understanding how structural order, aggregation, and vibrational coupling influence the optical and electronic properties of conjugated polymers is essential for optimizing their performance in optoelectronic devices. Here, we compare partially ordered MEH-PPV films prepared by the Langmuir–Blodgett (LB) technique with structurally disordered films obtained by drop-casting, as well as with the polymer in solution. UV–Vis absorption, steady-state photoluminescence, polarized spectroscopy, Raman scattering, and charge-transport measurements were employed. In solution, variations in the optical gap and Urbach tail with concentration reveal early aggregation effects manifested in the absorption tail prior to significant perturbation of the conjugated backbone. LB films exhibit partial orientational order, confirmed by absorption dichroism and polarized emission, whereas drop-cast films show similar optical response in perpendicular directions. Despite this orientational order, LB films show similar Urbach energies parallel and perpendicular to the dipping direction, indicating that the optical defect distribution is not direction-dependent, although a clear thickness dependence reveals the role of interface effects. Vibronic analysis (Huang–Rhys factor and effective conjugation length) demonstrates that LB deposition preferentially aligns polymer backbones with longer conjugation lengths and modifies the dominant vibrational modes coupled to emission, in agreement with Raman spectroscopy. Electrical current density vs. electric field measurements further distinguishes the two morphologies: partially ordered LB devices exhibit smoother and more stable transitions between ohmic and space-charge-limited current (SCLC), whereas disordered drop-cast devices reach the TFLC regime at lower fields, indicating a lower trap density distributed over a broader energy range. The comparison between optical (Urbach) and electrical (TFLC) analyses confirms that shallow optical traps and deep electrical traps probe distinct disorder populations. Acknowledgments: the Brazilian National Council for Scientific and Technological Development (CNPq) process number: 408449/2024-1, 420515/2023–2, 315710/2023–3, and 314034/2023–4; Fundação de Amparo à Pesquisa do Piauí (FAPEPI), Universidade Federal do Piauí (UFPI), Fundação de Amparo à Pesquisa de São Paulo (FAPESPI), Financiadora de Estudos e Projetos (FINPI)
Título do Evento
Workshop do INEO 2026
Cidade do Evento
Nazaré Paulista
Título dos Anais do Evento
Anais do Workshop do INEO 2026
Nome da Editora
Even3
Meio de Divulgação
Meio Digital

Como citar

AZEVEDO, Marleane Maria Felix de et al.. URBACH ENERGY: FILM PROCESSING AND THICKNESS EFFECTS.. In: Anais do Workshop do INEO 2026. Anais...Nazaré Paulista(SP) Hotel Estância Atibainha, 2026. Disponível em: https//www.even3.com.br/anais/workshop-do-ineo-2026/1465066-URBACH-ENERGY--FILM-PROCESSING-AND-THICKNESS-EFFECTS. Acesso em: 11/08/2026

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