DESIGN OF SINGLE MOLECULE AROMATIC MOLECULAR SWITCHES WITH METAL ELECTRODES-A COMPUTATIONAL APPROACH

Designed 1,4-benzene dithiol, 1,4-benzene diamine, and 1,4-benzene dicarboxylic acid based molecular switches with gold, silver, platinum and palladium metal electrodes by the first-principles approach. The electronic properties of the designed metal-moleculemetal sandwich structure are investigated with density functional theory (DFT) method. A series of benzene derivatives to explore the physical behaviour of conductance interpret in terms of nature of molecular backbone, anchoring group, contact geometry, nature of electrode material, molecular length, connectivity site, density of states, HOMO-LUMO gap, ionization potential and potential energy were systematically studied and compared. The findings of the present work clearly reveal that for the design of an efficient molecular switch, palladium and thiol are the best among electrode and anchoring group respectively. Palladium electrode shows high switching band gap ratio for ON and OFF state compared to Au, Ag, and Pt. The first principles approach can be used to screen and minimize the need for experimental approach which could be expensive