@article{205, keywords = {MBPT}, author = {Olivia Pulci and Elena Degoli and Federico Iori and Margherita Marsili and Maurizia Palummo and Rodolfo Del Sole and Stefano Ossicini}, title = {Electronic and optical properties of Si and Ge nanocrystals: An ab initio study}, abstract = {First-principles calculations within density functional theory and many-body perturbation theory have been carried out in order to investigate the structural, electronic and optical properties of undoped and doped silicon nanostructures. We consider Si nanoclusters co-doped with B and P. We find that the electronic band gap is reduced with respect to that of the undoped crystals, suggesting the possibility of impurity based engineering of electronic and optical properties of Si nanocrystals. Finally, motivated by recent suggestions concerning the chance of exploiting Ge dots for photovoltaic nanodevices, we present calculations of the electronic and optical properties of a Ge35H36 nanocrystal, and compare the results with those for the corresponding Si35H36 nanocrystals and the co-doped Si33BPH36.}, year = {2010}, journal = {Superlattices and Microstructures}, volume = {47}, number = {1}, pages = {178-181}, issn = {0749-6036}, url = {http://www.sciencedirect.com/science/article/B6WXB-4WSR0PT-2/2/4c35976f6fefbd70026cff2c92714f75}, doi = {DOI: 10.1016/j.spmi.2009.07.004}, note = {Proceedings of the 9th International Conference on Physics of Light-Matter Coupling in Nanostructures, PLMCN 2009 (Lecce - Italy)}, }