Cross-plane transport in a single-molecule two-dimensional van der Waals heterojunction
Shiqiang Zhao, Qingqing Wu, Jiuchan Pi, Junyang Liu, Jueting Zheng, Songjun Hou, Junying Wei, Ruihao Li, Hatef Sadeghi, Yang Yang, Jia Shi, Zhaobin Chen, Zongyuan Xiao, Colin J. Lambert, Wenjing Hong
Abstract
Two-dimensional van der Waals heterojunctions (2D-vdWHs) stacked from atomically thick 2D materials are predicted to be a diverse class of electronic materials with unique electronic properties. These properties can be further tuned by sandwiching monolayers of planar organic molecules between 2D materials to form molecular 2D-vdWHs (M-2D-vdWHs), in which electricity flows in a cross-plane way from one 2D layer to the other via a single molecular layer. Using a newly developed cross-plane break junction technique, combined with density functional theory calculations, we show that M-2D-vdWHs can be created and that cross-plane charge transport can be tuned by incorporating guest molecules. The M-2D-vdWHs exhibit distinct cross-plane charge transport signatures, which differ from those of molecules undergoing in-plane charge transport.