InAs Nanocrystal-Based Infrared Imager Operating beyond Telecom Wavelengths

Colloidal III–V nanocrystals offer a promising route toward cost-effective, CMOS-compatible infrared imaging beyond the silicon band gap. Here, we demonstrate a short-wave infrared (SWIR) imager operating at telecom wavelengths based on InAs nanocrystal photoconductors. InAs nanocrystals, with a spectral cutoff extending to 1600 nm, are synthesized and ligand-exchanged to produce an n-type conductive ink. A combination of photoemission, optical spectroscopy, and transport measurements enables a full determination of the electronic structure in the vicinity of the Fermi level, where the latter is quasi-degenerate with the conduction band and trap density is limited. Guided by these electronic characteristics, we fabricate an infrared-sensitized focal plane array using a single-step deposition process. The resulting imager enables room-temperature, real-time video imaging at telecom wavelengths under ambient operation, demonstrating the potential of III–V nanocrystal films for scalable infrared imaging technologies.