Chemical Physics and Dynamics of Surfaces – Plasmonics and sensors – Light matter coupling in nanocrystal array


  • Permanent members: Emmanuel Lhuillier, Yoann Prado
  • PhD students: Audrey Chu, Adrien Khalili, Huu Tung Dang


Design of the light matter coupling to achieve high absorption and spectral shaping

A central point in the design of infrared sensor using nanocrystal is the tradeoff between absorption and carrier transport. Absorption pushed toward thick film (1 µm and more) but this is incompatible with the short carrier diffusion length resulting from hopping transport. By integrating plasmonic resonator, such as guided mode resonator, we are able to focus the light on a thin slab of semiconductor and achieve absorption close to unity. This strategy can also be used to design on demand absorption spectral or to offer spectral tunability beyond the material quantum confinement.

Figure 1Left, spectrum of a nanocrystal based sensor with and without a guided mode resonator to enhance its absorption. Right, scheme of the device.

This task involved electromagnetic design and simulation for which we benefit from strong collaboration with Onera (G. Vincent) and LPENS (A. Vasanelli).


Figure 2Left, absorption spectrum of a PBS nanocrystal film coupled to a resonator along the two polarization. Right, comparison of the absorption spectra for non-resonant device and one with guided mode resonator.


This task also strongly relies on micro and nanofabrication. For this we benefit from INSP clean room and also from the one of consortium Paris centre. Below is a scheme of the targeted device to achieve enhanced absorption through the introduction of guided mode resonator

Figure 3 : fabrication de dispositif avec et sans résonateur.



  • Onera – Greogory Vincent
  • LPENS – A. Vasanelli



  • ERC BlackQD
  • Project ANR-DGA NITQuantum
  • ANR Copin and Frontal


Transversal topics



  1. Audrey Chu, Charlie Gréboval, Nicolas Goubet, Bertille Martinez, Clément Livache, et al.. Near Unity Absorption in Nanocrystal Based Short Wave Infrared Photodetectors using Guided Mode Resonators. ACS photonics, American Chemical Society,, 2019, ⟨10.1021/acsphotonics.9b01015⟩. ⟨hal-02281355⟩
  2. Prachi Rastogi, Audrey Chu, Charlie Gréboval, Junling Qu, Ulrich Nguétchuissi Noumbé, et al.. Pushing absorption of perovskite nanocrystals into the infrared. Nano Letters, American Chemical Society, 2020, 20 (5), pp.3999-4006. ⟨10.1021/acs.nanolett.0c01302⟩. ⟨hal-02542043⟩
  3. Prachi Rastogi, Audrey Chu, Tung Huu Dang, Yoann Prado, Charlie Gréboval, et al.. Complex Optical Index of HgTe Nanocrystal Infrared Thin Films and Its Use for Short Wave Infrared Photodiode Design. Advanced Optical Materials, Wiley, 2021, pp.2002066. ⟨10.1002/adom.202002066⟩. ⟨hal-03161581⟩