In the present theoretical work we have considered impurities, either boron or phosphorous, located at different substitutional sites in silicon quantum dots (Si-QDs) with diameters around 1.5 nm, embedded in a SiO2 matrix. Formation energy calculations reveal that the most energetically-favored doping sites are inside the QD and at the Si/SiO2 interface for P and B impurities, respectively. Furthermore, electron and hole transport calculations show in all the cases a strong reduction of the minimum voltage threshold, and a corresponding increase of the total current in the low-voltage regime. At higher voltages, our findings indicate a significant increase of transport only for P-doped Si-QDs, while the electrical response of B-doped ones does not stray from the undoped case. These findings are of support for the employment of doped Si-QDs in a wide range of applications, such as Si-based photonics or photovoltaic solar cells.
|Titolo:||Energetics and carrier transport in doped Si/SiO2 quantum dots.|
|Autori:||Garcia-Castello Nuria; Illera Sergio; Prades Joan Daniel; Ossicini Stefano; Cirera Albert; Guerra Roberto|
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||10.1039/c5nr02616d|
|Appare nelle tipologie:||1.1 Journal article|