Title: What's so special about nanocrystalline semiconductors?

Authors: Fabrizio Cleri, Pawel Keblinski

Addresses: Institute d'Electronique, Microelectronique et Nanotechnologie (CNRS UMR 8520), Universite de Sciences et Technologies de Lille, Avenue Poincare, B.P. 60069, Villeneuve d'Ascq 59652, France. ' Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA

Abstract: Nanocrystalline semiconductors display unique features compared to coarse-grained microstructures and even to their monocrystalline counterparts. We contend that such peculiarities are due to: (1) the extremely large fraction of atoms located at Grain Boundaries (GBs) and (2) the |character distribution| of GBs, which are mostly high-energy, random interfaces. Initially, we study the structure of random GBs in nanocrystalline semiconductors by means of large-scale Molecular Dynamics (MD) simulations. Subsequently, the atomic structure and electronic properties of some typical high-energy GBs in Si- and C-based nanostructures are characterised by means of a semi-empirical tight-binding Hamiltonian. We show that relevant properties of nanocrystalline semiconductors containing a large fraction of high-energy GBs are quite distinct with respect to those of coarse-grained and bulk semiconductors.

Keywords: grain boundaries; nanocrystalline semiconductors; electrical conductivity; molecular dynamics; tight-binding approximation; nanotechnology; nanoscale technology; grain boundary; simulation.

DOI: 10.1504/IJCSE.2006.012778

International Journal of Computational Science and Engineering, 2006 Vol.2 No.3/4, pp.242 - 249

Available online: 14 Mar 2007 *

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