Open AccessQuinoidal Small Molecule Containing Ring-Extended Termini for Organic Field-Effect Transistors
Author(s) -
Yoonjung Mok,
Yunseul Kim,
Yong-Tae Moon,
Jong-Jin Park,
Yeonsu Choi,
DongYu Kim
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c04120
Subject(s) - benzothiophene , organic field effect transistor , thiophene , materials science , molecule , band gap , electron mobility , organic semiconductor , small molecule , delocalized electron , polystyrene , ring (chemistry) , amorphous solid , crystallography , polymer , field effect transistor , optoelectronics , transistor , chemistry , organic chemistry , biochemistry , physics , quantum mechanics , voltage , composite material
In this work, we synthesized and characterized two quinoidal small molecules based on benzothiophene modified and original isatin terminal units, benzothiophene quinoidal thiophene (BzTQuT) and quinoidal thiophene (QuT), respectively, to investigate the effect of introducing a fused ring into the termini of quinoidal molecules. Extending the terminal unit of the quinoidal molecule affected the extension of π-electron delocalization and decreased the bond length alternation, which led to the downshifting of the collective Raman band and dramatically lowering the band gap. Organic field-effect transistor (OFET) devices in neat BzTQuT films showed p-type transport behavior with low hole mobility, which was ascribed to the unsuitable film morphology for charge transport. By blending with an amorphous insulating polymer, polystyrene, and poly(2-vinylnaphthalene), an OFET based on a BzTQuT film annealed at 150 °C exhibited improved mobility up to 0.09 cm 2 V -1 s -1 . This work successfully demonstrated that the extension of terminal groups into the quinoidal structure should be an effective strategy for constructing narrow band gap and high charge transporting organic semiconductors.