(Peer-Reviewed) A nonchlorinated solvent-processed polymer semiconductor for high-performance ambipolar transistors
Jie Yang 杨杰 ¹ ², Yaqian Jiang 蒋雅倩 ¹, Zhiyuan Zhao 赵志远 ¹, Xueli Yang 杨学礼 ¹, Zheye Zhang 张哲野 ², Jinyang Chen 陈金佯 ¹, Junyu Li ¹, Wei Shi 施薇 ¹, Shuai Wang 王帅 ², Yunlong Guo 郭云龙 ¹, Yunqi Liu 刘云圻 ¹
¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China 中国科学院 化学研究所 北京分子科学国家实验室 有机固体院重点实验室
² School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China 华中科技大学 化学与化工学院
Ambipolar polymer semiconductors are potentially serviceable for logic circuits, light-emitting field-effect transistors (LFETs), and polymer solar cells (PSCs). Although several high-performance ambipolar polymers have been developed, their optoelectronic devices are generally processed from hazardous chlorinated solvents. To achieve the commercial applications of organic FETs (OFETs), the polymers should be processed from nonchlorinated solvents, instead of chlorinated solvents.
However, most of conjugated polymers show poor solubility in nonchlorinated solvents. It is of great importance to develop ambipolar polymers that can be processed from nonchlorinated solvents. Here, we develop a nonchlorinated solvent processed polymer named poly[7-fluoro-N, N′-di(4-decyltetradecyl)-7′-azaisoindigo-6′,6″-(thieno[3,2-b]thiophene-2,5-diyl)-7‴-fluoro-N″, N‴-di(4-decyltetradecyl)-7″-azaisoindigo-6,6‴-([2,2'-bithiophene]-5,5'-diyl)] (PITTI-BT) by designing a monomer with a large molar mass.
The polymer displays good solubility in p-xylene (PX). Well-aligned films of PITTI-BT are achieved by an off-center spin-coating (SC) method. Based on the high-quality films, the OFETs fabricated from PX solution achieve record ambipolar performance with hole and electron mobilities of 3.06 and 2.81 cm2 V−1 s−1, respectively. The combination of nonchlorinated solvents and good alignment process offers an effective and eco-friendly approach to obtain high-performance ambipolar transistors.