Active Photonics from Nanocrystal Based Devices

Nanocrystals raised more and more interest relative to their integration into cost-effective infrared device and especially for imaging. I will start by reviewing some recent develoments made in the group than has lead to the development of photoconductive and photovoltaic mode for HgTe nanocrystals based camera operating in the short wave infrared. However, the quest for cost effectiveness can not be limited to the nanocrystal growth and should include the whole camera design especially the optics. This is why the second part of my talk will be focus on integrated optics coupled to whort wave infrared sensor. I will show how the coupling of such nanocrystal film to a photonic structure can be used to enhance the absorption and shape their spectral response. I will then discuss how the light matter coupling can me made active (i.e., post fabrication tunable). There, i will demonstrate that the unique coupling of hopping conduction and photonic cavity can bring nanocrystals in the famility of active photonic and be used to generate bias reconfigurable photoresponse.

Photoconductive focal plane array based on HgTe quantum dots for fast and cost-effective short-wave infrared imaging, C. Gréboval et al,, Nanoscale 14, 9359 (2022)
Stop blaming hopping conduction in nanocrystal arrays, use it for active photonics! N. Ledos et al, Adv mater Techn. 9, 2301463 (2024)
Bias reconfigurable photoresponse of infrared nanocrystal film integrated into a coupled nano Fabry Perot resonator, T. H. Dang, et al, ACS photonics 10, 1601 (2023)