ScholarWorks@동국대학교

초록

Photodetectors operating at the eye-safe wavelength of 1550 nm are essential for applications such as LiDAR and optical communications; however, achieving high responsivity with atomically thin materials remains challenging. Here, we report a quantum dot-coated graphene/MoS2 barristor photodetector enabling infrared detection via photogating-induced Schottky barrier modulation. Ligand-exchanged PbS quantum dots absorb 1550 nm light and transfer photoexcited carriers to graphene, modulating the Schottky barrier height (SBH) and inducing exponential current amplification. The device exhibits a current response of -2000% and a responsivity up to -780 A W- 1 at a MoS2 thickness of 4.5 nm, where a minimum SBH of -0.246 eV is extracted from thermionic emission analysis. These results demonstrate that thickness-engineered Schottky barrier modulation provides an effective strategy for high-responsivity infrared photodetectors based on two-dimensional heterostructures.

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