Chlorinated Conjugated Polymer Based on Chlorine‐ and Cyano‐substituted (E)‐1, 2‐Di(thiophen‐2‐yl)ethane for Ambipolar and n‐Type Organic Thin‐film Transistors. Issue 16 (17th June 2022)

• Record Type: Journal Article
• Authors: Zhang, Yulong; Zhang, Chan; Su, Yunran; Dong, Weijia; Li, Yanru; Liu, Zhongwei; Yao, Xiang; Han, Yang; Fei, Zhuping
• Is Part Of: Chinese journal of chemistry. Volume 40:Issue 16(2022)
• Page Start: 1957
• Page End: 1963
• Publication Date: 2022-06-17
• Subjects: Organic thin‐film transistors -- Semiconductors -- Chlorination -- Cross‐coupling -- C—H activation; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.202200209
• Languages: English
• ISSNs: 1001-604X

Abstract

Comprehensive Summary: Chlorinated conjugated polymers are rarely reported in ambipolar and n‐type organic thin‐film transistors (OTFTs), mainly due to the lack of chlorinated strong electron‐deficient building blocks. Herein, we report three new chlorine (Cl)‐ and cyano (CN)‐ substituted ( E )‐1, 2‐di(thiophen‐2‐yl)ethane building blocks and their copolymers P2Cl1CNTVT‐DPP, P4Cl1CNTVT‐DPP and P2Cl2CNTVT‐DPP. P2Cl1CNTVT‐DPP and P2Cl2CNTVT‐DPP had nearly planar backbone geometries, mixture of edge‐on and face‐on orientation and deeper energy levels, while P4Cl1CNTVT‐DPP had a twist backbone geometry, face‐on orientation and shallower energy levels. As a result, P2Cl1CNTVT‐DPP exhibited ambipolar characteristic with hole mobility ( μ h ) of 0.70 cm 2 ·V –1 ·s –1 and electron mobility ( μ e ) of 0.84 cm 2 ·V –1 ·s –1 and P2Cl2CNTVT‐DPP exhibited n‐type characteristic with μ e of 0.64 cm 2 ·V –1 ·s –1, while P4Cl1CNTVT‐DPP exhibited the lowest μ e of 0.36 cm 2 ·V –1 ·s –1 . The devices based on P2Cl2CNTVT‐DPP exhibited good stability after being stored for 10 d in air. The results demonstrate that by rational molecular design, chlorinated polymers with low cost can be applied to high‐performance ambipolar and n‐type OTFTs. Abstract : Three electron‐deficient building blocks based on chlorine‐ and cyano‐substituted ( E )‐1, 2‐di(thiophen‐2‐yl)ethane (TVT), and their corresponding copolymers with diketopyrrolopyrrole (DPP) via direct arylation polymerization are reported. The frontier molecular orbitals and polymer backbone geometry of these polymers could be regulated by the number and position of Cl and CN groups on TVT units. P2Cl1CNTVT‐DPP exhibited ambipolar transporting with relatively balanced μ e and μ h of 0.84/0.70 cm 2 ·V –1 ·s –1, and P4Cl1CNTVT‐DPP and P2Cl2CNTVT‐DPP exhibited n‐type transporting with μ e of 0.36 and 0.64 cm 2 ·V –1 ·s –1, respectively. The devices based on P2Cl2CNTVT‐DPP exhibited good air stability due to the stabilized LUMO level against atmospheric water and/or oxygen.