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Effect of fluctuations on the radiative rate in core/shell quantum dots

a-b) Experimental temperature dependence of the excited state lifetime for CdSe/CdS QD of a given core diameter and different total diameters. c-d) Calculated radiative lifetimes for CdSe/CdS QD . The effects of thermal excitation (dotted line), thermal fluctuations (dashed line), and both thermal excitation and fluctuations (solid) line are shown for all particle sizes studied.

Scientific Achievement
Determined the impact of lattice fluctuations on the radiative rate in core/shell quantum dots.

Significance and Impact
Better understanding the nature of the radiative state gives insight into further design of quantum dot heterostructures.

Research Details

  • Compared excited state lifetime of synthesized core/shell quantum dots to theoretical model.
  • Were able to show the contributions of thermal excitation, lattice fluctuations, and the combination of the two.
  • Results indicate that lattice fluctuations have the largest contribution, but including thermal excitation is important in capturing the experimental behavior.

Balan, A. D.; Eshet, H.; Olshansky, J. H.; Lee, Y. V.; Rabani, E.; Alivisatos, A. P. Nano Lett. 17, 1629-1636.(2017)