Silicon nanocrystals, ncSi, embedded in a dielectric matrix are presently studied in view of their application as tunable band-gap absorbers in all-silicon multijunction photovoltaicsa. Althoug high conductivity and high mobility are requirements for the matrix in order to guarantee an efficient carrier collection, the ideal properties of the ncSi are more related to the ability of absorbing photons beyond a given energy, and then emit the photogenerated carrier into the extended states of the surrounding matrix. At present, the role of doping in this context has not fully established, also because doping of nanocrystals suffers from limitations due to segregation at the surface and formation of electrically inactive complexes with dangling bondb, as well as size dependent activation efficiencyd. At the nanoscale, higher conductivity has also been observed either on the ncSi surface or within the ncSi itseld, depending on the doped of intrinsic nature of the ncSi.4. Finally, overlapping of the wavefunction, and therefore carrier collection efficiency, is also predicted to depend on the barirer height of the surrounding matrix. It is therefore very important to clarify the electrical behaviour of the ncSi when inserted in the specific matrix that will be used for the final device. In our case we focus on silicon carbide, which quarantees lower barrier to the ncSi, and better transport properties.

Doping of the Silicon Nanodots / Silicon Rich Carbide System

PERANI, MARTINA;CAVALCOLI, DANIELA;
2012

Abstract

Silicon nanocrystals, ncSi, embedded in a dielectric matrix are presently studied in view of their application as tunable band-gap absorbers in all-silicon multijunction photovoltaicsa. Althoug high conductivity and high mobility are requirements for the matrix in order to guarantee an efficient carrier collection, the ideal properties of the ncSi are more related to the ability of absorbing photons beyond a given energy, and then emit the photogenerated carrier into the extended states of the surrounding matrix. At present, the role of doping in this context has not fully established, also because doping of nanocrystals suffers from limitations due to segregation at the surface and formation of electrically inactive complexes with dangling bondb, as well as size dependent activation efficiencyd. At the nanoscale, higher conductivity has also been observed either on the ncSi surface or within the ncSi itseld, depending on the doped of intrinsic nature of the ncSi.4. Finally, overlapping of the wavefunction, and therefore carrier collection efficiency, is also predicted to depend on the barirer height of the surrounding matrix. It is therefore very important to clarify the electrical behaviour of the ncSi when inserted in the specific matrix that will be used for the final device. In our case we focus on silicon carbide, which quarantees lower barrier to the ncSi, and better transport properties.
2012
27th EU PVSEC
5
5
M. Canino; M. Allegrezza; R. Shukla; M. Bellettato; A. Desalvo;C. Summonte;M. Perani ; D. Cavalcoli; I. Jain; I. Crupi; A. Terrasi; S. Mirabella
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/151987
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