Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Interaction of GaN(0001)-2×2 surfaces with H2O

: Lorenz, P.; Gutt, R.; Haensel, T.; Himmerlich, M.; Schaefer, J.A.; Krischok, S.


Physica status solidi. C 7 (2010), No.2, pp.169-172
ISSN: 1610-1634
ISSN: 1610-1642
ISSN: 1862-6351
International Conference on the Formation of Semiconductor Interfaces (ICFSI) <12, 2010, Weimar>
Journal Article, Conference Paper
Fraunhofer IAF ()

We performed an in-situ analysis of the interaction of water with clean 2×2 reconstructed GaN(0001) surfaces grown by plasma assisted molecular beam epitaxy. The as-grown surfaces were exposed to molecular water by backfilling. Photoemission spectra reveal an extremely high reactivity and dissociative adsorption with an oxygen sticking coefficient of 0.3 and a saturation coverage of approximately 1 ML. Core level spectra of the O1s state show three individual oxygen components with different temporal behavior. Furthermore, the initial reconstruction quickly vanishes and surface states in the valence band of the as-grown surface are removed during the exposure of the first few Langmuirs. For higher exposures, two oxygen-related states appear. The initial upward band bending of 0.4 eV for the as-grown surface is effectively reduced during oxidation resulting in flat band conditions.