TY - JOUR
T1 - Thermal and structural dependence of the band gap of quantum dots measured by a transparent film heater
AU - Woo, Ju Yeon
AU - Tripathy, Suraj Kumar
AU - Kim, Kyungnam
AU - Han, Chang Soo
N1 - Funding Information:
This research was supported by the Industrial Strategic technology development program (MKE), the Center for Advanced Soft Electronics in Global Frontier Program and Green Nano Technology (MEST), Korea.
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/2/6
Y1 - 2012/2/6
N2 - We report the temperature dependence of the optical absorption and emission spectra of quantum dots (QDs) for three different nanocrystal (NC) structures (CdSe core, CdSe/CdS core/shell, and CdSe/CdS/ZnS core/multishell) in the solid film state. For this, a transparent single-walled carbon nanotube (SWCNT) film attached to a QD thin layer was tested as a heater. The temperature dependence of spectral shifts in both absorption and emission of QDs was measured in the range 300-450 K, and the Stokes shift was calculated by measuring the energy difference between the absorption and emission peaks. We found that the Stokes shift decreased as QD shells were added and the temperature was increased, indicating a weaker electron-phonon coupling in the QDs with additional shells at higher temperature. Finally, the band gap of the QDs was measured as a function of temperature. The Debye temperature was obtained by empirically fitting the energy band gap.
AB - We report the temperature dependence of the optical absorption and emission spectra of quantum dots (QDs) for three different nanocrystal (NC) structures (CdSe core, CdSe/CdS core/shell, and CdSe/CdS/ZnS core/multishell) in the solid film state. For this, a transparent single-walled carbon nanotube (SWCNT) film attached to a QD thin layer was tested as a heater. The temperature dependence of spectral shifts in both absorption and emission of QDs was measured in the range 300-450 K, and the Stokes shift was calculated by measuring the energy difference between the absorption and emission peaks. We found that the Stokes shift decreased as QD shells were added and the temperature was increased, indicating a weaker electron-phonon coupling in the QDs with additional shells at higher temperature. Finally, the band gap of the QDs was measured as a function of temperature. The Debye temperature was obtained by empirically fitting the energy band gap.
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U2 - 10.1063/1.3682515
DO - 10.1063/1.3682515
M3 - Article
AN - SCOPUS:84863165511
SN - 0003-6951
VL - 100
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 6
M1 - 063105
ER -