Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 20: Poster session
MM 20.31: Poster
Dienstag, 27. März 2007, 14:45–18:00, Poster C
Influence of bonding on the I-V-characteristics of Si29H24 and organic molecules on Si surfaces — •Samuel Baltazar-Rojas1,4, Daungruthai Jarukanont1, Mario De Menech1,2, Ulf Saalmann2, Aldo Romero3, and Martin Garcia1 — 1Theoretische Physik, FB 18, Universität Kassel, Kassel, Germany — 2Max–Planck–Institut für Physik komplexer Systeme, Dresden, Germany — 3CINVESTAV, Queretaro, Mexico — 4Advanced Materials Department, IPICYT, San Luis Potosi, Mexico
In the last years, much attention has been given to the study of transport properties through supported clusters and molecules, and it has become more intensive in the last years due to the different potential applications of these systems to electronic devices. We present a theoretical study of charge transport through clusters and molecules supported on silicon surfaces. The method simulates the measurement of the I-V characteristics with the help of a STM tip. The electronic properties of the cluster (molecule) coupled to the surface and the STM are calculated using non-equilibrium Green’s functions based on effective single-particle Hamiltonians. In particular, we have computed conductance spectra of H-passivated silicon cluster Si29H24 on an ideal Si surface, showing the importance of the surface to modulate and control the I-V curve. Also, we have considered organic molecules such as styrene and show that negative differential resistance can appear due to the shifting of the electronic levels near bulk of the Si substrate with the external bias. We analyze the effect for different configurations of the supported organic molecule.