Dresden 2011 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)

O 60.95: Poster

Wednesday, March 16, 2011, 17:30–21:00, P4

Electronic States of Polar and Non-polar Surfaces within the Quasiparticle Approach — •Abderrezak Belabbes and Friedhelm Bechstedt — Institut für Festköpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany

DFT provides an incorrect description of the band gap and excited states of InN. The correction of this error is of considerable importance in understanding the surface physics and semiconducting properties of InN. The purpose of this work is to reevaluate the quasiparticle band structure using the novel LDA-1/2 method for the surfaces states of InN. We restrict ourselves to a discussion of the electronic structure of the clean polar and non-polar surfaces. Our calculations allow us to explain the n-type conductivity of polar InN surfaces and the pinning of the Fermi level. The electronic structure of non-polar InN surfaces is found to be very different from that of the polar surface. It shows a semiconduting behavior, but with surfaces states that energetically overlap with bulk states. Therefore, these findings suggest an absence of electron accumulation on the non-polar InN surfaces. Our results agree with the previous calculations by C. G. Van de Walle and experimental observations by Wu et al, who provided evidence for an unpinned Fermi level at non-polar surfaces. The results have been obtained with low computational effort, similarly to standard LDA calculations, much in contrast to the GW quasiparticle approach.