Carrier dynamics in semiconductor quantum dots

Unlike many organic chromofores, semiconductor quantum dots can accomodate multiple excitations. Multiple excitation leads, however, to the opening of new and rapid non-radiative relaxation routes via an Auger mechanism, where an exciton recombines and transfers the energy to a spectator charge. By controlling the composition in a multicomponent ("onion") quantum dot, it is possible to control and utilize this relaxation mechanism.

We have been using a combination of ensemble and single-particle spectroscopy to investigate many unique pohenomena in these particles which exploit enahnced exciton-exciton interactions. In the past few years we have also been developing quantum spectroscopy - the use of temporal and spectral-temporal photon correlation information as an alternative or an addition to "conventional" time-, frequency- or k-space dependent spectroscopy. These efforts often rely on state-of-the-art SPAD array technology which enables us to perform experiments which were impossible until recently.

Recent publications:

  1. G. Yang, M. Kazes, D. Raanan, D. Oron, “Bright Near-Infrared to Visible Upconversion Double Quantum Dots Based on a Type-II/Type-I Heterostructure”, ACS Photonics 8, 1909 (2021).
  2. G. Lubin, R. Tenne, A. Ulku, I. M. Antolovic, S. Burri, S. Karg, V. J. Yallapragada, C. Bruschini, E. Charbon, D. Oron, “Heralded spectroscopy reveals exciton-exciton correlations in single colloidal quantum dots”, Nano Lett. 21, 6756 (2021).
  3. G. Lubin, G. Yaniv, M. Kazes, I. Antolovic, S. Burri, C. Bruschini, E. Charbon, V. J. Yallapragada, D. Oron, “Resolving the controversy in biexciton binding energy of cesium lead halide perovskite nanocrystals through heralded single-particle spectroscopy”, ACS Nano 15, 19581 (2021).
  4. G. Lubin, D. Oron, U. Rossman, R. Tenne, V.J. Yallapragada, “Photon Correlations in Spectroscopy and Microscopy”, ACS Photonics 9, 2891 (2022).
  5. S. Ghosh, U. Ross, A. M. Chizik, J. Kuo, B. K. Jeong, W. K. Bae, K. Park, J. Li, D. Oron, S. Weiss, J. Enderlein, A. I. Chizik, “Excitation intensity-dependent quantum yield of semiconductor nanocrystals”, J. Phys. Chem. Lett. 14, 2702 (2023).
  6. D. Amgar, G. Lubin, G. Yang, F. Rabouw, D. Oron, “Resolving the emission transition dipole moments of single doubly-excited seeded nanorods via heralded defocused imaging”, accepted for publication in Nano Lett. (2023).