Photonics and coherence of spin – Excitonic properties of colloidal nanocrystals

List of members


Internships and jobs






  • Permanent members: Thierry Barisien, Frédérick Bernardot, Maria Chamarro, Alex Chin, Laurent Legrand, Christophe Testelin

Semiconductor colloidal nanocrystals (NCs) currently attract a considerable attention for they combine several advantages: a relatively low production cost, a large diversity in their structures, capabilities for an incorporation in organic materials and outstanding optoelectronic properties. They are promising candidates as elementary bricks in various applications: classical displays, lasers (or more generally high optical gain-based applications) and single emitter-based bright quantum sources. The optimization of the emission and gain properties as well as the development of novel families (among which inorganic halide perovskite NCs) require a thorough understanding of the fundamental processes that govern the formation and relaxation of the NCs primary excitations (excitons).

In this context the conducted research focuses on the following topics:

  • The fine structure of band edge excitons : its characterization (levels structure and polarization of states) and how it is influenced by the crystal symmetry, the NC shape anisotropy, the level of confinement and dielectric confinement effects ;
  • The coupling of excitons to phonons and its impact on temporal coherence ;
  •  The exciton spin dynamics : including the characterization of exciton spin lifetime as well the study of the mechanisms leading to spin flip and decoherence (see also topic #2 in main page).


Experimental techniques

Optical absorption, time-resolved photoluminescence, micro-photoluminescence, magneto-optical spectroscopy & transient absorption (collaborative frame) – Low temperature (~5K) to room temperature measurements.



Controlling the shape anisotropy of colloidal nanocrystals to modify the effects of carrier confinement

Indirect excitons in colloidal core-crown nanoplatelets

New-generation nanocrystals reveal their emission properties

Recent and ongoing collaborations

  • @INSP : OCN Team (in Physurf, INSP),
  • Quantum Optics Group, Laboratoire Kastler Brossel, Sorbonne Université, École Normale Supérieure,
  • Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, Sorbonne Université, Université de Paris.
  • Laboratoire , Faculté des Sciences de Bizerte, Université de Carthage,
  • Optoelectronics Group, Cavendish Laboratory, University of Cambridge,
  • Quantum Chemistry Group, University Jaume I (Spain).
  • Laboratoire de Physique et d’Étude des Matériaux, ESPCI, Université PSL, ESPCI,
  • High Field Magnet Laboratory, Radboud University, Nijmeguen



  • ANR IPERNANO2 (2018-) “Inorganic PERovskite NANOcrystals for NANOphotonics” (coordination : Maria Chamarro)


Recent publications

  • R. Ben Aich, S. Ben Radhia, K. Boujdaria, M. Chamarro and C. Testelin. Multiband k·p Model for Tetragonal Crystals: Application to Hybrid Halide Perovskite Nanocrystals. J. Phys. Chem. Lett., 2020, 11, 808.
  • V. Steinmetz, J. Climente, R. Pandya, J. Planelles, F. Margaillan, Y. Puttisong, M. Dufour, S. Ithurria, A. Sharma, G. Lakhwani, L. Legrand, F. Bernardot, C. Testelin, M. Chamarro, A. Chin, A. Rao, T. Barisien. Emission State Structure and Linewidth Broadening Mechanisms in Type-II CdSe/CdTe Core–Crown Nanoplatelets: A Combined Theoretical–Single Nanocrystal Optical Study. J. Phys. Chem. C, 2020, 124, 17352.
  • R. Pandya, V. Steinmetz, Y. Puttisong, M. Dufour, W. M. Chen, R. Y. S. Chen, T. Barisien, A. Sharma, G. Lakhwani, A. Mitioglu, P. Christianen, L. Legrand, F. Bernardot, C. Testelin, A. W. Chin, S. Ithurria, M. Chamarro, A. Rao. Fine Structure and Spin Dynamics of Linearly Polarized Indirect Excitons in Two-Dimensional CdSe/CdTe Colloidal Heterostructures. ACS Nano, 2019, 13, 10140.
  • R. Ben Aich, I. Saidi, S. Ben Radhia, K. Boujdaria, T. Barisien, L. Legrand, F. Bernardot, M. Chamarro, C. Testelin. Bright-exciton splittings in inorganic cesium lead halide perovskite nanocrystals. Phys. Rev. Appl., 2019, 11, 034042.
  • J. Ramade, L. M. Andriambariarijaona, V. Steinmetz, N. Goubet, L. Legrand, T. Barisien, F. Bernardot, C. Testelin, E. Lhuillier, A. Bramati, M. Chamarro. Fine structure of excitons and electron–hole exchange energy in polymorphic CsPbBr3 single nanocrystals. Nanoscale, 2018, 10, 6393.