Plakat Wojciech Kamiński (P29-Pon)
BISTABLE H2PC MOLECULAR CONDUCTANCE SWITCH ON AG(100)
1 Instytut Fizyki Doświadczalnej, Uniwersytet Wrocławski, pl. Maksa Borna 9, 50-204 Wrocław, Polska
2 Instytut Fizyki Doświadczalnej, Uniwersytet Wrocławski, pl. Maksa Borna 9, 50-204 Wrocław, Polska
3 Physical Chemistry I, Ruhr-University of Bochum, Universitätsstraße 150, 44801 Bochum, Germany
Scanning tunneling microscopy (STM) and density functional theory (DFT) were used to study the tautomerization reaction of an H2Pc molecule adsorbed on a Ag(100) surface. The presence of two hydrogen atoms in the cavity of the H2Pc molecule enforces the existence of two molecular tautomers. It causes a reduction from four- to two-fold symmetry in STM images that can be recorded as two current states over the H2Pc molecule with a high-to-low current state ratio of ~1.2. These findings are confirmed by the spatial distributions of the allatom electron charge density calculated using DFT and transmission maps together with tunneling current ratios (~1.2) determined from non-equilibrium Green’s function transport calculations. Therefore, we demonstrate that an H2Pc molecule adsorbed on a Ag(100) surface is a good candidate for a bistable molecular conductance switch since neither the presence of the Ag(100) surface nor that of the STM tip alter the tautomerization.