title: Room-temperature electron spin dynamics in free-standing ZnO quantum dots.
abstract: Conduction band electrons in colloidal ZnO quantum dots have been prepared photochemically and examined by electron paramagnetic resonance spectroscopy. Nanocrystals of 4.6 nm diameter containing single S-shell conduction band electrons have g(*)=1.962 and a room-temperature ensemble spin-dephasing time of T(2)(*)=25 ns, as determined from linewidth analysis. Increasing the electron population leads to increased g(*) and decreased T(2)(*), both associated with formation of P-shell configurations. A clear relationship between T(2)(*) and hyperfine coupling with 67Zn(I=5/2) is observed.
authors.affiliation: Department of Chemistry and Center for Nanotechnology, University of Washington, Seattle, Washington 98195, USA.
authors.forename: William K
authors.initials: WK
authors.lastname: Liu
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Whitaker
authors.forename: Alyssa L
authors.initials: AL
authors.lastname: Smith
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Kittilstved
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Robinson
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gamelin
mesh_terms: D003102:Colloids / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D004583:Electrons; D009943:Organophosphorus Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D010777:Photochemistry; D045663:Quantum Dots; D019265:Spectroscopy, Near-Infrared; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D003102:Colloids; D009943:Organophosphorus Compounds; C044965:trioctyl phosphine oxide; D015034:Zinc Oxide