ISSN: 2319-9873
Ivan Stich
Slovak Academy of Sciences, Slovakia
Keynote: RRJET
We study low temperature on-surface species which come in form of reactive molecular oxygen species (ROS: O22-, O2-, OH), or oxygen single-atom quantum dots (SaQD: Oad2-, Oad-, Oad0) in ultra-high vacuum on semiconducting rutile TiO2(110)1��1 surface [1]. We show that the redox states of ROSs and SaQD can be manipulated by Kelvin Probe Force Spectroscopy and imaged by Atomic Force Microscopy. Rates of these electron tunneling processes are measured by a novel ultra-fast technique we developed [1]. Two very different applications of redox-state driven processes/devices will be demonstrated: 1) redox state driven reversible on-surface chemical reactions, such as 2 Oad2- � O22- [2], 2) ultra-fast redox state driven reversible oxygen adatom conductance switch [3]. Unlike in the much more studied molecular switches, in atomic switches the non-conducting�conducting transition is induced by redox state transition which only involves electronic, as opposed to atomic processes in molecular switches. All underlying models are supported by advanced density functional theory calculations.
Prof. Štich got his PhD. in condensed matter physics in Trieste, Italy in 1989. He worked at Cavendish Laboratory, in U.K. where in 1991 he ported, for the first time, plane-wave psedopotential calculations on parallel computers. In 1994 he joined the Joint Research Center for Atom Technology in Tsukuba, Japan. He got his full professorship in solid state physics at the Slovak Technical University in 2003. In addition to density functional techniques, he also works in many-body electronic structure, such as Quantum Monte Carlo. 2007-2011 he served as director of the Institute of Physics, Slovak Academy of Sciences. From 2011 he is head of the Center for Computational Materials Science. His current interests are in surface probe techniques (AFM, STM) and 2D systems.