Two-dimensional Quasi-Freestanding Molecular Crystals for   High-Performance Organic Field-Effect Transistors
  Two-dimensional atomic crystals are extensively studied in recent years due to their exciting physics and device applications. However, a molecular counterpart, with scalable processability and competitive device performance, is still challenging. Here, we demonstrate that high-quality few-layer dioctylbenzothienobenzothiophene molecular crystals can be grown on graphene or boron nitride substrate via van der Waals epitaxy, with precisely controlled thickness down to monolayer, large-area single crystal, low process temperature and patterning capability. The crystalline layers are atomically smooth and effectively decoupled from the substrate due to weak van der Waals interactions, affording a pristine interface for high-performance organic transistors. As a result, monolayer dioctylbenzothienobenzothiophene molecular crystal field-effect transistors on boron nitride show record-high carrier mobility up to 10cm2V-1s-1 and aggressively scaled saturation voltage around 1V. Our work unveils an exciting new class of two-dimensional molecular materials for electronic and optoelectronic applications. 
Daowei He, Yuhan Zhang, Qisheng Wu, Rui Xu, Haiyan Nan, Junfang Liu,   Jianjun Yao, Zilu Wang, Shijun Yuan, Yun Li, Yi Shi, ...
cond-mat.mtrl-sci