title: Colloidal semiconductor quantum dots with tunable surface composition.
abstract: Colloidal CdS quantum dots (QDs) were synthesized with tunable surface composition. Surface stoichiometry was controlled by applying reactive secondary phosphine sulfide precursors in a layer-by-layer approach. The surface composition was observed to greatly affect photoluminescence properties. Band edge emission was quenched in sulfur terminated CdS QDs and fully recovered when QDs were cadmium terminated. Calculations suggest that electronic states inside the band gap arising from surface sulfur atoms could trap charges, thus inhibiting radiative recombination and facilitating nonradiative relaxation.
authors.affiliation: Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: Helen Hsiu-Ying
authors.initials: HH
authors.lastname: Wei
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Evans
authors.forename: Brett D
authors.initials: BD
authors.lastname: Swartz
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Neukirch
authors.forename: Jeremy
authors.initials: J
authors.lastname: Young
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Prezhdo
authors.forename: Todd D
authors.initials: TD
authors.lastname: Krauss
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D010316:Particle Size; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D019187:Cadmium Compounds; D003102:Colloids; D046911:Macromolecular Substances; D018036:Selenium Compounds; C058667:cadmium selenide