Dresden 2006 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
HL: Halbleiterphysik
HL 3: III-V semiconductors I
HL 3.7: Talk
Monday, March 27, 2006, 11:45–12:00, POT 51
Atomically resolved imaging of the GaAsN(110) surface — •V. Vossebürger1, D. Martin1, L. Ivanova1, A. Lenz1, R. Timm1, H. Eisele1, M. Dähne1, O. Schuhmann2, L. Geelhaar2, and H. Riechert2 — 1Technische Universität Berlin, Institut fürFestkörperphysik, Hardenbergstr. 36, D-10623 Berlin — 2Infinion Technologies, Corporate Research Photonics,D-81730 München
GaAs1−xNx is a highly interesting
material because of its giant composition dependent optical bowing,
which is
theoretically described by the band anticrossing model (BAC)[1].
In order to determine the arrangement of nitrogen atoms in GaAsN
alloys with low nitrogen concentration x between 1% and 2% as well
as its electronic structure, cross-sectional scanning tunneling
microscopy (XSTM) and spectroscopy (XSTS) experiments were performed
of GaAsN layers in GaAs grown by molecular beam epitaxy (MBE).
Using high resolution voltage dependent XSTM images and
simultaneously acquired XSTS images, we derive a structure model of
the GaAsN(110) surface. In differential conductance spectra,
displaying the local density of states, we observe a reduced band
gap and an additional nitrogen-induced state. This state is related
to
the theoretically found band splitting in the BAC model.
This work was supported by the SFB 296, and project Da 408/8 of the DPG.
[1] W. Shan et al., Phys. Rev. Lett. 82, 1221 (1999)