Millimeter-Sized Two-Dimensional Molecular Crystalline Semiconductors with Precisely Defined Molecular Layers via Interfacial-Interaction-Modulated Self-Assembly

• Published in: The journal of physical chemistry letters 2018-12, Vol.9 (23), p.6755-6760
• Main Authors: Jiang, Sai, Qian, Jun, Duan, Yiwei, Wang, Hengyuan, Guo, Jianhang, Guo, Yu, Liu, Xinyi, Wang, Qijing, Shi, Yi, Li, Yun
• Format: Article
• Language: English
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.8b03108

The newly emerging field in organic electronics is to control the molecule–substrate interface properties at a two-dimensional (2D) limit via interfacial interactions, which paves the way for driving the molecular assembly for highly ordered 2D molecular crystalline films with precise molecular layers and large-area uniformity. Here, by exploiting molecule–substrate van der Waals (vdW) interactions, we demonstrate thermally induced self-assembly of 2D organic crystalline films exhibiting well-defined molecular layer number over a millimeter-sized area. The organic field-effect transistors (OFETs) with bilayer films show excellent electrical performance with a maximum mobility of 12.8 cm2 V–1 s–1. Moreover, we find that the monolayer films can act as interfacial molecular templates to construct heterojunctions with well-balanced ambipolar transport behaviors. The capability of thermally induced self-assembly of 2D molecular crystalline films with controllable molecular layers and scale-up coverage opens up a way for realizing complicated electronic applications, such as lateral heterojunctions and superlattices.