| AVS 59th Annual International Symposium and Exhibition | |
| Electron Transport at the Nanoscale Focus Topic | Thursday Sessions |
| Session ET+SS+GR+SP-ThA |
| Session: | Electron Transport at the Nanoscale: Molecules and Defects |
| Presenter: | L. Adamska, University of South Florida |
| Authors: | L. Adamska, University of South Florida M. Kozhushner, Institute of Chemical Physics, Russian Academy of Sciences I.I. Oleynik, University of South Florida |
| Correspondent: | Click to Email |
Single-molecule rectification has been recently observed using the STM modulated break-junction technique in non-symmetric diblock dipyrimidinyl-diphenyl molecule covalently bound to metallic electrodes. To provide an insight to the nature of the rectification, first-principles calculations of atomic, electronic and transport properties of gold/molecule/gold junctions have been performed for both symmetrical tetraphenyl and asymmetrical dipyrimidinyl-diphenyl diblock molecules. The charge transport was found to occur by hole resonant tunneling mechanism via positively-charged hole states of the molecule, which are very susceptible to the external electric field and dispersive interactions with the metallic electrodes. It was found that the rectification effect in chemically-assymetric dipyrimidinyl-diphenyl molecule is due to strong localization of the hole wave function at one end of the diblock under applied electric field. Such behavior is contrasted by symmetric I-V curves exhibited by symmetric tetraphenyl molecule.