Enhanced Short-Wavelength Infrared Photodetector Based on PbS Quantum Dots with NiO Hole-Extraction Layer

초록

With the rapid development of automation technologies such as autonomous driving and smart factories, thedemand for reliable infrared photodetectors in light detection and ranging (LIDAR) systems has increased. Conventionalepitaxial compound-semiconductor detectors are costly and operate in the near-infrared (NIR) region, which poses safetyrisks to the human eye. To address these issues, we developed a short-wavelength infrared (SWIR) photodetector based onPbS quantum dots (QDs) that can absorb light in the eye-safe region (1400–1500 nm) through particle size control and lowcostsolution processing. However, solvent interference between the QDs and hole-extraction layers reduces film uniformityand stability. In this study, a NiO thin film was deposited by radiofrequency (RF) sputtering as a hole-extraction layer toform a quantum well structure, which improved hole extraction efficiency and infrared transmittance. A ZnO nanoparticleelectron-extraction layer was additionally applied to balance charge transport and suppress recombination. The optimizedNiO/ZnO dual-layer device exhibited excellent band alignment, enhanced optical transparency, and a high responsivity of115%. These results demonstrate the feasibility of non-cooled, eye-safe SWIR photodetectors for future autonomous andindustrial sensing applications.

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