Electronic States and Luminescence in Porous Silicon Quantum Dots: The Role of Oxygen

M. V. Wolkin; J. Jorne; P. M. Fauchet; G. Allan; C. Delerue

doi:10.1103/PhysRevLett.82.197

Electronic States and Luminescence in Porous Silicon Quantum Dots: The Role of Oxygen

M. V. Wolkin, J. Jorne, P. M. Fauchet, G. Allan, and C. Delerue

Phys. Rev. Lett. 82, 197 – Published 4 January 1999

Abstract

Depending on the size, the photoluminescence (PL) of silicon quantum dots present in porous silicon can be tuned from the near infrared to the ultraviolet when the surface is passivated with Si-H bonds. After exposure to oxygen, the PL shifts to the red by as much as 1 eV. This shift and the changes in PL intensity and decay time, show that both quantum confinement and surface passivation determine the electronic states of silicon quantum dots. A theoretical model in which new electronic states appear in the band gap of the smaller quantum dots when a $Si = O$ bond is formed, is in good agreement with experiments. This result clarifies the controversy regarding the PL mechanisms in porous silicon.

Received 25 September 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.197

Authors & Affiliations

M. V. Wolkin, J. Jorne^*, and P. M. Fauchet^†

Materials Science Program, University of Rochester, Rochester, New York 14627

G. Allan and C. Delerue

Département Institut Supérieur d'Electronique du Nord, Institut d'Electronique et de Microélectronique du Nord, 41 boulevard Vauban 59046 Lille cédex, France