title: Spectrally resolved dynamics of energy transfer in quantum-dot assemblies: towards engineered energy flows in artificial materials.
abstract: We report on the dynamics of resonant energy transfer in monodisperse, mixed-size, and energy-gradient (layered) assemblies of CdSe nanocrystal quantum dots. Time-resolved and spectrally resolved photoluminescence directly reveals the energy-dependent transfer rate of excitons from smaller to larger dots via electrostatic coupling. The data show a rapid (0.7-1.9 ns) energy transfer directly across a large tens-of-meV energy gap (i.e., between dots of disparate size), and suggest that interdot energy transfer can approach picosecond time scales in structurally optimized systems.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Crooker
authors.forename: J A
authors.initials: JA
authors.lastname: Hollingsworth
authors.forename: S
authors.initials: S
authors.lastname: Tretiak
authors.forename: V I
authors.initials: VI
authors.lastname: Klimov