Work

Fast-response infrared photodetector based on PbS quantum dots for integrated photonic devices characterization

Year: 2025

Type: article

Abstract: Integrating functionalized quantum dot (QD) components on integrated photonic circuits is an enabling technology to realize unprecedented optical functionalities beyond the capacities of passive photonic devices. Here, we demonstrate a fast-response infrared lead sulfide (PbS) QD photodetector operating at 1550 nm wavelength. Fabricated by a low-cost layer-by-layer process on a 2 cm × 2 cm glass substrate, this device is compatible with wafer-scale large-volume manufacturing. We systematically characterize the absorption properties of the QD solution, QD film, and the final fabricated photodetectors. Our photodetector exhibits a responsivity of 2.61 × 10 −3 A/W at zero bias, which is further boosted to 0.16 A/W at −1 V bias, with photoresponse spanning the telecom S- and C-bands. The photodetector features a -3 dB bandwidth of 4 kHz and a rapid rise time of 86.7 µs. For the first time, we showcase the photodetector in acetylene gas absorption spectroscopy and high-Q tantalum pentoxide microresonator transmission spectrum characterizations, and achieve excellent agreement with the results measured by commercial detectors. This work presents a critical step towards fully integrated QD-incorporated optoelectronic circuits, paving the way to complicated integrated photonic systems that could be deployed for on-chip sensing, optical communication, and optical computing.

Source: Optics Express

DOI: 10.1364/oe.581982