posted on 2020-03-06, 15:37authored bySha Yang, Shuang Li, Guo-Xu Zhang, Sergey N. Filimonov, Christopher J. Butch, Ji-Chang Ren, Wei Liu
A central
difficulty in the design of molecular electronics is
poor control of the contact state between the molecule and metal electrode,
which may induce instability and noise in logic and memory devices
and even destroy the intrinsic functionality of the device. Here,
we theoretically propose a simple and effective strategy for realizing
full control of the contact state of organic molecules coated on the
metal surface by applying homogeneous surface strain. As exemplified
by pyrazine molecules on Cu(111), application of compressive (tensile)
strain causes the molecules to uniformly adopt the physisorbed (chemisorbed)
state. Within the framework of non-equilibrium Green’s function
calculations, we show that the two distinct contact states yield simultaneous
rectification and switching behaviors. Because the contact states
of all surface-bound molecules are transformed uniformly via surface
strain perturbations, fully controlled collective switching and rectification
effects can be simultaneously achieved in this contact system.