title: Energetics and carrier transport in doped Si/SiO2 quantum dots.
abstract: 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.
authors.affiliation: MIND-IN2UB, Department of Electronics, Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain. nuriagarcia@ub.edu.
authors.forename: Nuria
authors.initials: N
authors.lastname: Garcia-Castello
authors.forename: Sergio
authors.initials: S
authors.lastname: Illera
authors.forename: Joan Daniel
authors.initials: JD
authors.lastname: Prades
authors.forename: Stefano
authors.initials: S
authors.lastname: Ossicini
authors.forename: Albert
authors.initials: A
authors.lastname: Cirera
authors.forename: Roberto
authors.initials: R
authors.lastname: Guerra