Temperature Dependence of the Drift Mobility of Poly(9,9 '-dioctylfluorene-co-benzothiadiazole)-Based Thin-Film Devices

Autor(es)

Faria, G. C. ; Faria, R. M. ; deAzevedo, E. R. ; von Seggern, H.

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 115, n. 51, p. 5-pg., 2011-12-29.

Resumo

Charge transport in spin coated thin films of poly(9,9'-dioctylfluorene-co-benzothiadiazole) (F8BT) was studied using the Photo-Current Extraction by the Linear Increasing Voltage (Photo-CELIV) method in the temperature range of 120 to 420 K. A continuous change in the slope of a In mu versus T-2 plot was detected at 205 K with a very weak temperature dependence of the mobility at lower temperatures. According to the Gaussian Disorder Model (GDM), this behavior can be attributed to a progressive decrease in the dispersiveness of the charge transport. In this sense, the weak temperature dependence of the mobility at low temperatures arises from the nonequilibrium condition between thermal released and trapped charges, so the transport becomes trap controlled at low temperature. Furthermore, another change in the mobility behavior was observed at about 360 K, which was related to the glass transitions of the material. This indicates that even for thin films the drift mobility can be significantly affected by a variation in the dynamics and local packing of the polymer chains, which can be detected by Photo-CELIV (AU)

• Processo FAPESP: 09/18354-8 - Dinâmica e estrutura de sistemas poliméricos estudados por ressonância magnética nuclear
• Beneficiário: Eduardo Ribeiro de Azevedo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/08688-0 - Dispositivos eletrônicos e optoeletrônicos poliméricos
• Beneficiário: Roberto Mendonça Faria
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/01935-5 - Correlação das propriedades óticas e elétricas com a estrutura física e dinâmica molecular de filmes e dispositivos orgânicos de polifluorenos e derivados
• Beneficiário: Gregório Couto Faria
• Modalidade de apoio: Bolsas no Brasil - Doutorado