ARTICLE pubs.acs.org/JPCC
The Second Order Nonlinear Susceptibility of Quantum Confined Semiconductors—A Single Dot Study Shoshana Winter,† Marcin Zielinski,‡ Dominique Chauvat,‡ Joseph Zyss,‡ and Dan Oron*,† † ‡
Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel Laboratoire de Photonique Quantique et Moleculaire Ecole Normale Superieure de Cachan 61 avenue du President Wilson, 94230 Cachan Cedex (France) and Laboratoire Europeen Associe NABI, CNRS-Weizmann D’Alembert Institute
bS Supporting Information ABSTRACT: Detection of the second harmonic generation from single CdTe quantum dots of ∼11.5 nm diameter enables us to obtain an absolute value for the nonlinear susceptibility χ(2) of these nanoparticles as well as their dispersion properties. These measurements, complemented by ensemble hyper-Rayleigh scattering characterization, elucidate the role of quantum confinement in the second harmonic generation process. We show that, under similar excitation conditions, the χ(2) of quantum dots can significantly exceed that of the corresponding bulk material. The results indicate that by careful choice of excitation wavelength and material, kilo-counts per second rates of second harmonic generation photons can be obtained from quantum dots with
