Shape dependence of the scattering processes of optical phonons in colloidal nanocrystals detected by Raman Spectroscopy

Krahne, Roman and Chilla, Gerwin and Schueller, Christian and Kudera, Stefan and Tari, Davide and De Giorgi, Milena and Heitmann, Detlef and Cingolani, Roberto and Manna, Liberato (2006) Shape dependence of the scattering processes of optical phonons in colloidal nanocrystals detected by Raman Spectroscopy. JOURNAL OF NANOELECTRONICS AND OPTOELECTRONICS, 1 (1). pp. 104-107. ISSN 1555-130X,

Full text not available from this repository.

Abstract

We investigated by Raman spectroscopy optical phonon excitations in colloidal CdTe nanocrystals of different shapes. The phonon spectra at excitation energies slightly below the absorption onset showed a strong dependence on the nanocrystal shape. For spherical nanocrystals, we detected broad longitudinal-optical phonon-scattering peaks that were blue shifted from the longitudinal-optical phonon bulk energy by the exciton resonant Stokes shift. These are reminiscent of the phonon replicas reported in fluorescence line-narrowing experiments. Tetrapod-shaped nanocrystals, on the other hand, showed a sharp LO phonon peak that was only slightly blue shifted by confinement effects on the phonon excitations. We propose that the localization of the carriers in the optical excitations is responsible for the different phonon spectra in tetrapods.

Item Type: Article
Uncontrolled Keywords: SEMICONDUCTOR QUANTUM RODS; CDTE NANOCRYSTALS; DOTS; SURFACE; NANOWIRES; CLUSTERS; EXCITON; GROWTH; STATES; DARK;
Subjects: 500 Science > 530 Physics
Divisions: Physics > Institute of Experimental and Applied Physics
Depositing User: Dr. Gernot Deinzer
Date Deposited: 17 Feb 2021 09:15
Last Modified: 17 Feb 2021 09:15
URI: https://pred.uni-regensburg.de/id/eprint/34749

Actions (login required)

View Item View Item