TY - JOUR
T1 - Exciton-phonon coupling and disorder in the excited states of CdSe colloidal quantum dots
AU - Salvador, Mayrose R.
AU - Graham, Matthew W.
AU - Scholes, Gregory D.
N1 - Funding Information:
The Natural Sciences and Engineering Research Council of Canada, Canadian Foundation for Innovation, Ontario Innovation Trust, and Photonics Research Ontario are gratefully acknowledged for financial support. One of the authors (G.D.S.) thanks the Alfred P. Sloan Foundation.
PY - 2006
Y1 - 2006
N2 - We study the origin of the spectral line shape in colloidal CdSe nanocrystal quantum dots. The three-pulse photon echo peak shift (3PEPS) data reveal a temperature-independent fast decay, obscuring the quantification of the homogeneous linewidth. The optical gap and Stokes shift are found to have an anomalous behavior with temperature, which is size, capping group, and surrounding polymer matrix independent. Using these results and combining them with simulations, we discuss the role of exciton-phonon coupling, static inhomogeneity, exciton fine structure, and exciton state disorder in the linewidth of the nanocrystal. In particular, our analysis shows that the disorder due to surface imperfections and finite temperature effects, as well as the relaxation within the fine structure, can have significant impact on the steady-state absorption spectrum, 3PEPS data, and dephasing processes.
AB - We study the origin of the spectral line shape in colloidal CdSe nanocrystal quantum dots. The three-pulse photon echo peak shift (3PEPS) data reveal a temperature-independent fast decay, obscuring the quantification of the homogeneous linewidth. The optical gap and Stokes shift are found to have an anomalous behavior with temperature, which is size, capping group, and surrounding polymer matrix independent. Using these results and combining them with simulations, we discuss the role of exciton-phonon coupling, static inhomogeneity, exciton fine structure, and exciton state disorder in the linewidth of the nanocrystal. In particular, our analysis shows that the disorder due to surface imperfections and finite temperature effects, as well as the relaxation within the fine structure, can have significant impact on the steady-state absorption spectrum, 3PEPS data, and dephasing processes.
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U2 - 10.1063/1.2363190
DO - 10.1063/1.2363190
M3 - Article
C2 - 17115781
AN - SCOPUS:33751003554
SN - 0021-9606
VL - 125
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 18
M1 - 184709
ER -