Optical properties of tetrapod-shaped CdTe nanocrystals

• Published in: Applied physics letters Vol. 87; no. 22; pp. 224101 - 224101-3
• Main Authors: Tarì, Davide, De Giorgi, Milena, Sala, Fabio Della, Carbone, Luigi, Krahne, Roman, Manna, Liberato, Cingolani, Roberto, Kudera, Stefan, Parak, Wolfgang J.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 28-11-2005
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2130727

We studied the carrier confinement in tetrapod-shaped colloidal CdTe nanocrystals by means of absorption, photoluminescence, and photoluminescence excitation spectroscopy at room and cryogenic temperatures. The spectra show features characteristic of the tetrapod shape together with a clear dependence on the dominant confinement parameter, i.e., the diameter of the tetrapod arm. Theoretical calculations based on an envelope-function approximation and using the exact tetrapod shape have been performed to assign the observed spectral features. Oscillator strength and size dependence of the transitions energy have been calculated showing a direct correlation between the oscillator strength and the nanocrystal shape.