title: Highly efficient Blue-Emitting CdSe-derived Core/Shell Gradient Alloy Quantum Dots with Improved Photoluminescent Quantum Yield and Enhanced Photostability.
abstract: Highly efficient blue-emitting CdSe-derived core/shell gradient alloy quantum dots (CSGA QDs) with photoluminescence quantum yield (PL QY) of ca. 90% have been synthesized through a facile "one-pot" approach. CdSe nuclei are initially formed as core and gradient alloy shells such as CdSexS1-x/ZnSeyS1-ysimultaneously encapsulate the preformed CdSe core in an energy-gradient fashion eventually followed by coating with ZnS shells due to the faster precursor reaction kinetics of Cd and Se compared to analog of Zn and S. During the formation of core/shell structure, red-shifting of absorption/emission peaks followed by blue-shifting of analogues were observed due to the intradiffusion of sulfur anion to CdSe luminescent center. In this gradient architecture, interfacial lattice strain can be effectively alleviated, and thus high PL QY (ca. 90%) and enhanced photochemical stability can be achieved. The synthesized blue-emitting gradient alloy QDs with superior optical properties tunable in the range of 450-490 nm can be used for highly efficient blue-emitters and potentially applicable for the fabrication of white-light LEDs.
authors.affiliation: Department of Chemistry, Seoul National University , Seoul 151-747, Korea.|Department of Chemistry, Texas A&M University , College station, Texas 77843, United States.
authors.forename: Junsang
authors.initials: J
authors.lastname: Cho
authors.affiliation: Department of Chemistry, Seoul National University , Seoul 151-747, Korea.|Display R&D Center, Samsung Display Co., Ltd., Yongin 446-711, Korea.
authors.forename: Yun Ku
authors.initials: YK
authors.lastname: Jung
authors.affiliation: Department of Chemistry, Seoul National University , Seoul 151-747, Korea.
authors.forename: Jin-Kyu
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Seoul National University , Seoul 151-747, Korea.|Laboratory of Molecular Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health , 50 South Drive, Building 50, Bethesda, Maryland 20892, United States.
authors.forename: Hak-Sung
authors.identifier: 0000-0002-1391-3154
authors.initials: HS
authors.lastname: Jung