Development of Lead-free Ag2Te QDs-based Photodetector for SWIR Detection

초록

Recent advancements in autonomous driving and urban air mobility technologies have significantly increased the demand for infrared photodetectors. Short-wave infrared (SWIR) imaging provides improved image resolution compared with that of near-infrared imaging owing to its lower scattering and higher transmittance characteristics. Conventional commercialized SWIR-band photodetectors, such as InSb, Ge, HgCdTe, and InGaAs require complex manufacturing processes, resulting in high production costs and the need for additional cooling devices. Therefore, research on alternative materials, such as quantum dots (QDs), for SWIR photodetection is crucial. QDs are particularly promising candidates as photoactive materials owing to their relatively simple processing requirements and exceptional absorption characteristics at specific wavelength bands. Ag<inf>2</inf>Te QDs do not contain heavy metals (Pb, Hg, etc.), thereby complying with the European directive Restriction of Hazardous Substances. This study synthesized lead-free Ag<inf>2</inf>Te QDs with an absorption peak at 1670 nm, which corresponds to the eye-safe band, and fabricated a high-sensitivity SWIR photodetector. Additionally, to enhance the sensitivity of the device, P3HT (Poly(3-hexylthiophene-2,5-diyl)) and ZnO nanoparticles were incorporated as hole/electron extraction layers. As the results, the fabricated SWIR photodetector was confirmed to be capable of detecting an eye-safe wavelength laser of 1670 nm with a responsivity of up to 184.2%. © 2024, Korean Sensors Society. All rights reserved.

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