The role of local fields in the optical response of silicon nanocrystals is analyzed using a tight binding approach. Our calculations show that, at variance with bulk silicon, local field effects dramatically modify the silicon nanocrystal optical response. An explanation is given in terms of surface electronic polarization and confirmed by the fair agreement between the tight binding results and that of a classical dielectric model. From such a comparison, it emerges that the classical model works not only for large but also for very small nanocrystals. Moreover, the dependence on size of the optical response on the nanocrystal size is discussed, in particular treating the limit of large size nanocrystals.
Role of local fields in the optical properties of silicon nanocrystals using the tight binding approach / F., Trani; Ninno, Domenico; G., Iadonisi. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 75:(2007), pp. 33312-1-33312-4. [10.1103/PhysRevB.75.033312]
Role of local fields in the optical properties of silicon nanocrystals using the tight binding approach
NINNO, DOMENICO;
2007
Abstract
The role of local fields in the optical response of silicon nanocrystals is analyzed using a tight binding approach. Our calculations show that, at variance with bulk silicon, local field effects dramatically modify the silicon nanocrystal optical response. An explanation is given in terms of surface electronic polarization and confirmed by the fair agreement between the tight binding results and that of a classical dielectric model. From such a comparison, it emerges that the classical model works not only for large but also for very small nanocrystals. Moreover, the dependence on size of the optical response on the nanocrystal size is discussed, in particular treating the limit of large size nanocrystals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.