標題: Influences of Conjugation Length on Organic Field-Effect Transistor Performances and Thin Film Structures of Diketopyrrolopyrrole-Oligomers
作者: Huang, Yi-Fan
Chang, Shu-Ting
Wu, Kuan-Yi
Wu, San-Lien
Ciou, Guan-Ting
Chen, Chin-Yi
Liu, Cheng-Liang
Wang, Chien-Lung
應用化學系
Department of Applied Chemistry
關鍵字: diketopyrrolopyrrole;conjugation length;grain boundary;crystallinity;organic semiconductor
公開日期: 14-三月-2018
摘要: Here, two diketopyrrolopyrrole (DPP)-based oligomers, DPP-4T and DPP-6T, are studied to reveal the influences of conjugation length on thin-film morphology and organic field-effect transistor (OFET) performances. PDMS-assisted crystallization in a solvent-annealing chamber is applied to prepare crystal arrays of DPP-4T and DPP-6T to optimize the quality of charge channels for OFET characterizations. To deliver insights into microstructure and morphology of thin films, a characterization procedure for determining molecular packing in thin film and crystallinity of the crystal arrays is presented via grazing incidence wide-angle X-ray scattering, electron diffraction, and lattice simulation software package (Cerius2). With the lattice parameters derived from analyses of grazing incidence wide-angle X-ray scattering (GIWAXS) and electron diffraction (ED), the lattice modeling results indicate that the inferior organic field-effect transistor (OFET) performances of DPP-6T are attributed to longer pi-stacking distance. Also, less-ordered molecular arrangement and lower continuity of crystalline domains, both of which are revealed from crystallinity results, lead to lower mobility of DPP-6T. In this case, longer conjugated backbones with more conformational degrees of freedom thus cause inherent crystal defects during the crystal growth process, despite the potential to enhance intermolecular pi-orbital overlap. Therefore, to achieve better OFET performance, suitable backbone length makes conjugated oligomers give high intermolecular pi-orbital overlap and low density of structural disorder, which are the priorities for constructing good charge channel.
URI: http://dx.doi.org/10.1021/acsami.7b15983
http://hdl.handle.net/11536/144706
ISSN: 1944-8244
DOI: 10.1021/acsami.7b15983
期刊: ACS APPLIED MATERIALS & INTERFACES
Volume: 10
起始頁: 8869
結束頁: 8876
顯示於類別:期刊論文