Berlin 2012 – scientific programme

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

HL: Fachverband Halbleiterphysik

HL 11: Carbon: Nanotubes, Diamond and Silicon Carbid

HL 11.1: Talk

Monday, March 26, 2012, 11:45–12:00, EW 203

Electronic properties of silicon carbide surfaces and interfaces — •Andre Konopka, Tim Baumgarten, Siegmund Greulich-Weber, Eva Rauls, Wolf Gero Schmidt, and Uwe Gerstmann — Physics, University of Paderborn, Paderborn, Germany

Micro- and nanocrystalline materials provide new applications not only because of their potential to shrink devices, but also due to their new electrical and optical properties. Understanding the origin of these properties is essential to design and optimize these materials and the resulting devices. In these systems properties of surfaces and interfaces can dominated that of the bulk. Microcrystalline silicon carbide (µc-SiC) have become an attractive new class of advanced microstructured materials for optoelectronic applications due to their wide band gap and advanced chemical and mechanical properties. We use a sol-gel process for growing µc-SiC allowing arbitrary doping. To understand the origin of our experimental results [1,2] we performed theoretical calculations in the framework of density functional theory (DFT). In this work we present the results of different surfaces of SiC. We discuss how the electronic properties of the different surfaces interact with n- and p-type doping of SiC. Based on this calculations we propose a model that explains the charge transfer at an interface between SiC and an organic semiconductor. The calculated surface band structures can also help to understand other experimental results, like conductivity and EPR signatures.

[1] A. Konopka et al (2010) IOP Conf. Ser.: Mater. Sci. Eng. 15 012013, [2] A. Konopka et al (2011). MRS Proceedings, 1322