title: Two-photon-pumped lasing from colloidal nanocrystal quantum dots.
abstract: Upconverted lasing in the nonlinear, two-photon absorption regime has been demonstrated, for the first time to the best of our knowledge in colloidal nanocrystal quantum dots (NQDs). Upon pulse excitation at sub-bandgap photon energies the radiative recombination of excitons in close-packed CdSe/CdS/ZnS core-shell NQDs was found to be sufficiently fast to compete with the intrinsic nonradiative Auger recombination, as confirmed by the presence of a fast decay (approximately 7 ps) in the time-resolved photoluminescence.
authors.affiliation: Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhang
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Zhu
authors.forename: An
authors.initials: A
authors.lastname: Cheng
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Mohney
authors.forename: Ron H
authors.initials: RH
authors.lastname: Henderson
authors.forename: Y Andrew
authors.initials: YA
authors.lastname: Wang