Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 33: Poster I: Transport, including Magnetic-Field Effects

HL 33.1: Poster

Tuesday, March 23, 2010, 18:30–20:30, Poster D1

Atomistic Description of Large Nanostructures based on III-Nitride semiconductors — •Alejandro Molina-Sánchez¹, Alberto García-Cristóbal¹, Andres Cantarero¹, Aleksandrs Terentjevs², and Giancarlo Cicero² — ¹Instituto de Ciencia de Materiales de la Universidad de Valencia, P.O. Box 22085, E-46071 Valencia, Spain — ²Physics and Materials Science and Chemical Engineering Departments, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy

Semiconductor nanocolumns exhibiting a growth without dislocatinos and high crystalline quality are of great interest in nanotechnology applications. Specifically, InN-based nanocolumns are good candidates to develop multi-junction solar cells due to their small gap, 0.67 eV, and the posibility of alloying with other nitrides (as GaN and AlN) to cover the entire solar spectrum. A proper description of optical properties of the nanostructures described above can start with an atomistic treatment of the electronic structure in order to keep the essential geometry and symmetry of the objects. Unfortunately, the best description realized with ab initio electronic structure software is strongly limited by the nanocolumn diameter to a few nanometers. By using a combination of ab initio and empirical tight-binding methods, we can connect the quality of the first principles calculations (performed with the Espresso code), with the versatility of an empirical approach. Once we have an ab initio quality parameter set for the empirical tight-binding code, we can study larger nanostructures with this approach, reducing the computation time in orders of magnitud.