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. These include the first observation of carrier multiplication process in type-II core/shell quantum dot heterostructures and studies elucidating the origin of luminescence interittency in quantum dots..

We have, more recently, been developing colloidal double quantum dots - two coupled quantum dots packaged into a single nanocrystal, and exhibiting unique properties from two-color antibunching, through controlled blinking to photoluminescence upconversion. See our recent review on the topic "Colloidal double quantum dots" in Accounts of Chemical Research.

Recent publications:

  1. A. Teitelboim, D. Oron, “Broadband near-infrared to visible upconversion in quantum dot-quantum well heterostructures”, ACS Nano 10, 446 (2016).
  2. R. Tenne, S. Pedetti, M. Kazes, S. Ithurria, L. Houben, B. Nadal, D. Oron, B. Dubertret, "From dilute isovalent substitution to alloying in CdSeTe nanoplates", Phys. Chem. Chem. Phys. 18, 15292 (2016).
  3. N. Meir, B. Martín-García, I. Moreels, D. Oron, “Revisiting the anion framework conservation in cation exchange processes”, Chem. Mat. 28, 7872 (2016).
  4. A. Ben Moshe, A. Teitelboim, D. Oron, G. Markovich, “Probing the Interaction of Quantum Dots with Chiral Capping Molecules using Circular Dichroism Spectroscopy”, Nano Lett. 16, 7467 (2016).
  5. S. Luo, M. Kazes, H. Lin, D. Oron, “Strain induced Type-II band alignment control in CdSe nanoplatelets / ZnS sensitized solar cells”, J. Phys. Chem. C 121, 11136 (2017).
  6. G. Yang, M. Kazes, D. Oron, “Chiral 2D Colloidal Semiconductor Quantum Wells”, Adv. Funct. Mat. 1802012 (2018).