p-n heterojunctions composed of two-dimensional molecular crystals for high-performance ambipolar organic field-effect transistors
Jiarong Yao,
Xinzi Tian,
Shuyuan Yang,
Fangxu Yang,
Rongjin Li,
Wenping Hu
Affiliations
Jiarong Yao
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Xinzi Tian
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Shuyuan Yang
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Fangxu Yang
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Rongjin Li
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Wenping Hu
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Bilayer p-n heterojunctions are promising structures to construct ambipolar organic field-effect transistors (aOFETs) for organic integrated circuits. However, due to the lack of effective strategies for high-quality p-n heterojunctions with clear interfaces, the performance of aOFETs is commonly and substantially lower than that of their unipolar counterparts, which hinders the development of aOFETs toward practical applications. Herein, a one-step solution crystallization strategy was proposed for the preparation of high-quality bilayer p-n heterojunctions. A mixed solution of a p- and an n-type organic semiconductor was dropped on a liquid substrate, and vertical phase separation occurred spontaneously during crystallization to produce bilayer p-n heterojunctions composed of molecularly thin two-dimensional molecular crystals. Due to the clear interface of the bilayer p-n heterojunctions, the maximum mobility (average mobility) reached 1.96 cm2 V−1 s−1 (1.12 cm2 V−1 s−1) for holes and 1.27 cm2 V−1 s−1 (0.61 cm2 V−1 s−1) for electrons in ambient air. So far as we know, these values were the highest among double-channel aOFETs measured in ambient air. This work provides a simple yet efficient strategy to construct high-quality bilayer p-n heterojunctions, which lays a foundation for their application in high-performance optoelectronic devices.
