title: Room-temperature exciton storage in elongated semiconductor nanocrystals.
abstract: The excited state of colloidal nanoheterostructures consisting of a spherical CdSe nanocrystal with an epitaxially attached CdS rod can be perturbed effectively by electric fields. Field-induced fluorescence quenching coincides with a conversion of the excited state species from the bright exciton to a metastable trapped state (dark exciton) characterized by a power-law luminescence decay. The conversion is reversible so that up to 10% of quenched excitons recombine radiatively post turn-off of a 1 micro s field pulse, increasing the delayed luminescence by a factor of 80. Excitons can be stored for up to 10(5) times the natural lifetime, opening up applications in optical memory elements.
authors.affiliation: Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universität, Amalienstrasse 54, 80799 München, Germany.
authors.forename: R M
authors.initials: RM
authors.lastname: Kraus
authors.forename: P G
authors.initials: PG
authors.lastname: Lagoudakis
authors.forename: A L
authors.initials: AL
authors.lastname: Rogach
authors.forename: D V
authors.initials: DV
authors.lastname: Talapin
authors.forename: H
authors.initials: H
authors.lastname: Weller
authors.forename: J M
authors.initials: JM
authors.lastname: Lupton
authors.forename: J
authors.initials: J
authors.lastname: Feldmann