Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 42: Interfaces/surfaces

HL 42.1: Vortrag

Donnerstag, 26. März 2009, 09:30–09:45, POT 51

How a hydrogen passivated surface could appear to be metallic: the story of the 3C-SiC (001) 3x2 surface — •Peter Deak, Balint Aradi, and Thomas Frauenheim — Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, D-28359 Bremen, Germany

Photo electron and scanning tunneling spectroscopy has revealed partially filled states near the conduction band edge of the silicon rich (3x2)-reconstructed (001) surface of cubic SiC, after exposure to atomic hydrogen. These were attributed to a row of unsaturated singly occupied Si dangling bonds by experimentalists, and to a defect band due to a row of Si-H-Si tri-center bonds by theorists. Here we show that the surface is, in fact, completely passivated by hydrogen (no partially filled defect band) but, in doped samples, the accumulation of conduction band electrons at a polar surface can explain the experimental observations.