Infrared Imaging Using Thermally Stable HgTe/CdS Nanocrystals

• DOI: 10.1021/acs.nanolett.4c00907
• Publication Date: 2024-04-12T18:46:01Z
• Authors: Huichen Zhang; Yoann Prado; Rodolphe Alchaar; Henri Lehouelleur; Mariarosa Cavallo; Tung Huu Dang; Adrien Khalili; Erwan Bossavit; Corentin Dabard; Nicolas Ledos; Mathieu G Silly; Ali Madouri; Daniele Fournier; James K. Utterback; Debora Pierucci; Victor Parahyba; Pierre Potet; David Darson; Sandrine Ithurria; Bartłomiej Szafran; Benjamin T. Diroll; Juan I. Climente; Emmanuel Lhuillier
• Keywords: Thermal Stability

Transferring nanocrystals (NCs) from the laboratory environment toward practical applications has raised new challenges. HgTe appears as most spectrally tunable infrared colloidal platform. Its low-temperature synthesis reduces growth energy cost yet also favors sintering. Once coupled to a read-out circuit, Joule effect aggregates particles, leading poorly defined optical edge and large dark current. Here, we demonstrate that CdS shells bring expected thermal stability (no redshift upon annealing, reduced tendency form amalgams, preservation of photoconduction after an atomic layer deposition process). The electronic structure these confined particles is unveiled using k.p self-consistent simulations showing significant exciton binding ∼200 meV. After shelling, material displays p-type behavior generation photoconductive gain. latter then used increase external quantum efficiency imager, which now reaches 40% while presenting long-term stability.