Precise control from the bottom-up for realizing tunable functionality is of utmost importance to facilitate the development of molecular electronic devices.Until now,however,manipulating charge carriers over single-m...Precise control from the bottom-up for realizing tunable functionality is of utmost importance to facilitate the development of molecular electronic devices.Until now,however,manipulating charge carriers over single-molecule scale remains intractable.The origin of the problem is that the nature of charge carriers is often hindered by the complexity of the investigated molecular systems.Here,via ab initio simulations,we show a force-modulated and switched ambipolar single-molecule junction with Au/cyclopropane-1,2-dithiol/Au structure.The cyclopropane ring in the molecule can be opened and closed reversibly and repeatedly by the mechanical force.This structural transition from its closed state to open state enables the ambipolarity in charge carriers—from p-type to n-type.Analysis of electronic structure reveals unambiguously the force-dependent correlation between C–S bond order and the nature of charge carriers.Based on this,we design a binary interconnected junction exhibiting resistance,rectification and negative differential resistance functionalities under mechanical modulation,i.e.,loading/unloading or pull/push.This interesting phenomenon provides both illuminating insight and feasible controllability into charge carriers in molecules,and a very general idea and useful approach for single-molecule junctions in practical single-molecule devices.展开更多
基金the financial support of NSFC(Nos.11402312,11474363,11232015)the National Key Basic Research Program of China(No.2015CB351905)+3 种基金support by the Fundamental Research Funds for the Central Universities to Micro&Nano Physics and Mechanics Research LaboratoryFok Ying Tung FoundationScience and Technology Innovation Project of Guangdong Provincial Education DepartmentGuangdong Natural Science Funds for Distinguished Young Scholar.
文摘Precise control from the bottom-up for realizing tunable functionality is of utmost importance to facilitate the development of molecular electronic devices.Until now,however,manipulating charge carriers over single-molecule scale remains intractable.The origin of the problem is that the nature of charge carriers is often hindered by the complexity of the investigated molecular systems.Here,via ab initio simulations,we show a force-modulated and switched ambipolar single-molecule junction with Au/cyclopropane-1,2-dithiol/Au structure.The cyclopropane ring in the molecule can be opened and closed reversibly and repeatedly by the mechanical force.This structural transition from its closed state to open state enables the ambipolarity in charge carriers—from p-type to n-type.Analysis of electronic structure reveals unambiguously the force-dependent correlation between C–S bond order and the nature of charge carriers.Based on this,we design a binary interconnected junction exhibiting resistance,rectification and negative differential resistance functionalities under mechanical modulation,i.e.,loading/unloading or pull/push.This interesting phenomenon provides both illuminating insight and feasible controllability into charge carriers in molecules,and a very general idea and useful approach for single-molecule junctions in practical single-molecule devices.
