title: Optical imaging of electrical carrier injection into individual InAs quantum dots.
abstract: We image the micro-electroluminescence (EL) spectra of self-assembled InAs quantum dots (QDs) embedded in the intrinsic region of a GaAs p-i-n diode and demonstrate optical detection of carrier injection into a single QD. Tunneling of electrons and holes into the QDs at bias voltages below the flat-band condition leads to a spectrum of sharp EL lines from a small number of bright spots on the diode surface, characteristic of emission from individual QDs. We explain this behavior in terms of Coulomb interaction effects and the selective excitation of a small number of QDs within the ensemble due to preferential tunneling paths for carriers.
authors.affiliation: School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom. andreas.baumgartner@unibas.ch
authors.forename: A
authors.initials: A
authors.lastname: Baumgartner
authors.forename: E
authors.initials: E
authors.lastname: Stock
authors.forename: A
authors.initials: A
authors.lastname: Patanè
authors.forename: L
authors.initials: L
authors.lastname: Eaves
authors.forename: M
authors.initials: M
authors.lastname: Henini
authors.forename: D
authors.initials: D
authors.lastname: Bimberg