title: Doping location-dependent energy transfer dynamics in Mn-doped CdS/ZnS nanocrystals.
abstract: Dynamics of energy transfer and charge carrier localization in Mn-doped CdS/ZnS core/shell nanocrystals correlated with doping location and concentration are studied via transient absorption measurement of exciton relaxation dynamics. The strong dependence of exciton-Mn energy transfer rate on doping location was directly resolved in the transient bleach recovery and electron intraband absorption data by using layer-by-layer synthesized Mn-doped nanocrystals. With 1.2 nm decrease in doping radius in the ZnS shell, energy transfer rate increases by 6 fold. We identified that hole trapping is the major competing process that inhibits the energy transfer in Mn-doped CdS/ZnS nanocrystals. From the branching ratio of the energy transfer and hole trapping, combined with luminescence quantum yield measurement, we also obtained doping location-dependent radiative relaxation quantum yield of Mn(2+) ions that is as high as 0.95.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA.
authors.forename: Hsiang-Yun
authors.initials: HY
authors.lastname: Chen
authors.forename: Sourav
authors.initials: S
authors.lastname: Maiti
authors.forename: Dong Hee
authors.initials: DH
authors.lastname: Son
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003198:Computer Simulation; D004735:Energy Transfer; D008345:Manganese / Q000737:chemistry*; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D018036:Selenium Compounds / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D017967:Zinc Compounds; D008345:Manganese; C058667:cadmium selenide; C044696:zinc selenide