The Study Of Electronic Transport Properties Of Mercapto Group Containing Benzene Molecules

Studying the properties of molecules and clusters, especially on electronic transport characteristics, density functional theory (DFT) is very suitable for this field. It is very effective and precise theory of researching the electronic characteristics of two polar system.Many calculation software,which take it as theoritical dasis,are used in theoretical and experimental research in the field of physics and chemistry.Today,computer becomes very faster,so many DFT calculation software can be used to solve atomic and macro system.The calculation precision aso fufil the requirement.,First-principles calculations is used on the molecules which contain benzene ring.We made up five mercapto groups containing benzene molecules.We have built the models of molecules in ATK(ATOMISTIX TOOLKIT) and VNL(VIRTUAL NANOLAB).Then analysising the structure of molecules.Two Au(111)electrodes are also built in the software.In every model, there is a molecule which contains benzene ring in the middle of two probe system. Three mercapto groups containing benzene molecules are chosen as molecule bridges and their electronic transport properties are studied by using first-principles calculations and non-equilibrium Green's function method. The calculated results show that the change of the conductance of the three systems occurs in steps, i.e., the conductance is quantized. The variation laws of the conductance are similar to each other, but the conductance values decrease with increasing of the benzene. The lower energy electrons are not easy to pass through the molecular bridges compared to higher energy electrons.