Intramolecular Locked Dithioalkylbithiophene-Based Semiconductors for High-Performance Organic Field-Effect Transistors
Journal
Advanced Materials
Journal Volume
29
Journal Issue
35
Date Issued
2017
Author(s)
Vegiraju, S.
Chang, B.-C.
Priyanka, P.
Huang, D.-Y.
Wu, K.-Y.
Li, L.-H.
Chang, W.-C.
Lai, Y.-Y.
Hong, S.-H.
Yu, B.-C.
Chang, W.-J.
Liu, C.-L.
Chen, M.-C.
Facchetti, A.
Abstract
New 3,3'-dithioalkyl-2,2'-bithiophene (SBT)-based small molecular and polymeric semiconductors are synthesized by end-capping or copolymerization with dithienothiophen-2-yl units. Single-crystal, molecular orbital computations, and optical/electrochemical data indicate that the SBT core is completely planar, likely via S(alkyl)⋯S(thiophene) intramolecular locks. Therefore, compared to semiconductors based on the conventional 3,3'-dialkyl-2,2'-bithiophene, the resulting SBT systems are planar (torsional angle <1°) and highly π-conjugated. Charge transport is investigated for solution-sheared films in field-effect transistors demonstrating that SBT can enable good semiconducting materials with hole mobilities ranging from ≈0.03 to 1.7 cm2 V-1 s-1 . Transport difference within this family is rationalized by film morphology, as accessed by grazing incidence X-ray diffraction experiments.
Type
journal article