CdSe/ZnS Colloidal Quantum Dots with Alloyed Core/Shell Interfaces: A Photoluminescence Dynamics Study
K. Dziatkowskia,b, D. Ratchford a, T. Hartsfield a, X. Li a, Y. Gao c and Z. Tang c

aDepartment of Physics, University of Texas at Austin, Austin TX 78712, USA
bFaculty of Physics, University of Warsaw, Hoża 69, 00-681 Warsaw, Poland
cNational Center for Nanoscience and Technology, 100190 Beijing, P.R. China
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Time-resolved photon counting technique was employed to study dynamics of photoluminescence from the ensemble and single CdSe/ZnS quantum dots with the alloyed core/shell interfaces. The ensemble data revealed enhanced effect of disorder-induced trap states for increasing emission energy, as implied from the changes in the distribution of total decay rates. The emission trajectories collected for single quantum dots showed familiar, two-state blinking pattern. It suggests that in a large-band-offset CdSe/ZnS system, the introduced alloying of the core-to-shell region cannot smooth enough the confinement potential in order to suppress nonradiative Auger recombination and blinking.
DOI: 10.12693/APhysPolA.120.870
PACS numbers: 78.67.Hc, 78.47.jd, 78.55.Et