Inhalt des Dokuments
The atomic structure and electronic properties of the non-polar GaN(1-100) cleavage surface was studied using XSTM. GaN is the base material for the development of novel high-efficiency light emitters.
In our experiments we found that the surface is unreconstructed, and that there are no intrinsic surface states within the band gap . Furthermore we found different dislocation types and could derive their burgers vectors, line directions, and charge states . In addition, we could observe a modulation of the doping concentration during growth in  direction .
(a) XSTM image of a perfect screw dislocation crossing the GaN(1-100) surface  and (b) XSTM contrast variation due to a Si doping modulation .
 Surface states and origin of the Fermi level pinning on nonpolar GaN(1-100) surfaces, L. Ivanova, S. Borisova, H. Eisele, M. Dähne, A. Laubsch, and Ph. Ebert, Applied Physics Letters 93, 192110 (2008).
 Electronic properties of dislocations in GaN investigated by scanning tunneling microscopy, Ph. Ebert, L. Ivanova, S. Borisova, H. Eisele, A. Laubsch, and M. Dähne, Applied Physics Letters 94, 062104 (2009).
 Doping modulation in GaN imaged by cross-sectional scanning tunneling microscopy, H. Eisele, L. Ivanova, S. Borisova, M. Dähne, M. Winkelnkemper, and Ph. Ebert, Applied Physics Letters 94, 162110 (2009).