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.
- 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).
- 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).
- 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).
- G. Lubin, D. Oron, U. Rossman, R. Tenne, V.J. Yallapragada, “Photon Correlations in Spectroscopy and Microscopy”, ACS Photonics 9, 2891 (2022).
- 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).
- 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).