Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots
Acousticlike vibrations were observed in spontaneous Raman measurements on Cd Te0.68 Se0.32 quantum dots embedded in a borosilicate matrix and ascribed to the l=0, l=2, and l=1 modes of a spherical particle. Pump-probe stimulated Raman measurements on the same sample reveal only the symmetric l=0 mo...
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todo:paper_10980121_v73_n12_p_Bragas2023-10-03T16:05:58Z Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots Bragas, A.V. Aku-Leh, C. Merlin, R. Acousticlike vibrations were observed in spontaneous Raman measurements on Cd Te0.68 Se0.32 quantum dots embedded in a borosilicate matrix and ascribed to the l=0, l=2, and l=1 modes of a spherical particle. Pump-probe stimulated Raman measurements on the same sample reveal only the symmetric l=0 mode, the frequency of which increases as the laser central energy moves to higher energies. Consistent with the strong dependence of the exciton energy on the particle size, such a behavior is attributed to resonant size-selective excitation of nanocrystallites whose absorption edge coincides with the central energy of the optical pulses. This selectivity, relying on the existence of double-resonant terms in the generation process, is not observed in spontaneous Raman scattering for which the resonances involve a single term. © 2006 The American Physical Society. Fil:Bragas, A.V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_10980121_v73_n12_p_Bragas |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| description |
Acousticlike vibrations were observed in spontaneous Raman measurements on Cd Te0.68 Se0.32 quantum dots embedded in a borosilicate matrix and ascribed to the l=0, l=2, and l=1 modes of a spherical particle. Pump-probe stimulated Raman measurements on the same sample reveal only the symmetric l=0 mode, the frequency of which increases as the laser central energy moves to higher energies. Consistent with the strong dependence of the exciton energy on the particle size, such a behavior is attributed to resonant size-selective excitation of nanocrystallites whose absorption edge coincides with the central energy of the optical pulses. This selectivity, relying on the existence of double-resonant terms in the generation process, is not observed in spontaneous Raman scattering for which the resonances involve a single term. © 2006 The American Physical Society. |
| format |
JOUR |
| author |
Bragas, A.V. Aku-Leh, C. Merlin, R. |
| spellingShingle |
Bragas, A.V. Aku-Leh, C. Merlin, R. Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots |
| author_facet |
Bragas, A.V. Aku-Leh, C. Merlin, R. |
| author_sort |
Bragas, A.V. |
| title |
Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots |
| title_short |
Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots |
| title_full |
Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots |
| title_fullStr |
Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots |
| title_full_unstemmed |
Raman and ultrafast optical spectroscopy of acoustic phonons in Cd Te0.68 Se0.32 quantum dots |
| title_sort |
raman and ultrafast optical spectroscopy of acoustic phonons in cd te0.68 se0.32 quantum dots |
| url |
http://hdl.handle.net/20.500.12110/paper_10980121_v73_n12_p_Bragas |
| work_keys_str_mv |
AT bragasav ramanandultrafastopticalspectroscopyofacousticphononsincdte068se032quantumdots AT akulehc ramanandultrafastopticalspectroscopyofacousticphononsincdte068se032quantumdots AT merlinr ramanandultrafastopticalspectroscopyofacousticphononsincdte068se032quantumdots |
| _version_ |
1807316788244905984 |