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Type: 
Journal
Description: 
Innovative materials and quantum structures are required to increase the efficiency of PV cells. Beyond Si quantum dots (QD), Ge nanostructures begin to attract a growing attention because of lower melting point and energy gap with respect to Si. Moreover, the larger excitons Bohr radius in Ge (~ 20 nm, quadruple than in Si) would permit to exploit the confinement effect at a larger size with respect to Si … Recently, Ge QDs embedded in SiO2 have been realized by deposition of a SiGeO alloy layer (by magnetron co-sputtering) followed by thermal annealing up to 800°C. Such Ge QDs showed an optical bandgap of 1.6 eV, well higher than that of not-confined Ge (~ 0.7 eV), but independent of the QDs size [1]. At the same time, a strong relation between the QDs size and the absorption probability has been evidenced, pointing out that the photon absorption can be mediated by electronic states localized at the surface of the Ge QDs [1].
Publisher: 
The Electrochemical Society
Publication date: 
1 Aug 2011
Authors: 

Salvo Mirabella, Antonella Gentile, Salvo Cosentino, Nicolo Piluso, Giuseppe Nicotra, Emilia Esposito, Marco Camalleri, Francesca Simone, Antonio Terrasi

Biblio References: 
Issue: 29 Pages: 2015-2015
Origin: 
Meeting Abstracts