Programmable molecular-scale diode based on standard molecules/2D semiconductor hybrid molecular junction

Since Aviram and Ratner initially proposed the possibility of a molecular-scale rectifier in 1974, diverse type of molecular diodes driven by a specific molecular itself or the asymmetric coupling has been extensively demonstrated [1-2]. In this study, we propose a new class of molecular diode based on a hybrid molecular junction system that is composed with the 2D semiconductor (MoS₂ or WSe₂) and the standard self-assembled monolayer (SAM) (alkyl- or conjugated molecules). The 2D semiconductor and the SAM are sandwiched between the Au probe tip and Au bottom electrode using conductive atomic force microscopy (CAFM) technique. In the case of the molecular junction with monolayer MoS₂ and OPT2, the diode feature with rectification ratio > ~10³ was observed. Furthermore, the rectification ratio can be programmed according to the number of MoS₂ layers, the type of 2D semiconductor, molecular length, and molecular group. Our suggested rectifier architecture can provide potential benefits to simply implement the molecular diode function and propose the idea to improve the diode performance.
[1] Avriram, A.; Ratner, M. A. Chem. Phys. Lett. 1974, 29, 277-283
[2] Diez-Perez, I.; Hihath, J.; Lee, Y.; Yu, L.; Adamska, L.; Kozhushner, M. A.; Oleynik, I. I.; Tao, N. Nat. Chem. 2009, 1, 635-641