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. Lubin, D. Oron, U. Rossman, R. Tenne, V.J. Yallapragada, “Photon Correlations in Spectroscopy and Microscopy”, ACS Photonics 9, 2891 (2022).
  2. 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”, Nano Lett. 23, 5417 (2023).
  3. N. Frenkel, E. Scharf, G. Lubin, A. Levi, Y.E. Panfil, Y. Ossia, J. Planelles, J.I. Climente, U.  Banin, D. Oron, “Two Biexciton Types Coexisting in Coupled Quantum Dot Molecules”, ACS Nano 17, 14990 (2023).
  4. M. Kazes, D. Nakar, I. Cherniukh, M. Bodnarchuk, L. Feld, C. Zhu, D. Amgar, G. Raino, M. Kovalenko, D. Oron, “Observation of three-photon cascaded emission from triexcitons in giant CsPbBr3 quantum dots at room temperature”, Nano Lett. 24, 13185 (2024).
  5. K. Crans, H. Cohen, A. Nehoray, D. Oron, M. Kazes, R.L. Brutchey, “A redox active ionic liquid surface treatment for healing CsPbBr3 nanocrystals”, Nano Lett. 24, 16015 (2024).
  6. D. Amgar, D. Nakar, N. Frenkel, D,  D. Oron, “Correlations in the Binding Energy of Triexcitons and Biexcitons in Single CdSe/CdS Nanoplatelets Revealed by Heralded Spectroscopy”, J. Phys. Chem. Lett. 16, 11267 (2025).