InAs Nanocrystal-Based Infrared Imager Operating beyond Telecom Wavelengths.

Park, Youngsang; Jeong, Hyeonjun; Khalili, Adrien; Park, Seongmin; Guer, Quentin; Gureghian, Clement; Gemo, Tommaso; Roh, Jiho et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

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.