Long-wave infrared photothermoelectric detectors with resonant nanophotonics

Abstract

Photothermoelectric (PTE) detectors, renowned for their ultra-broadband photodetection capabilities at room temperature without requiring an external power supply, are pivotal for advancing infrared and terahertz detection technologies. Despite significant advancements with high-performance PTE detectors utilizing low-dimensional nanomaterials like graphene, persistent challenges such as low optical absorption efficiency and the complexities of scaling integration processes continue to restrict enhancements in device integration and wavelength scalability. Here, we introduce a high-performance long-wave infrared (LWIR) PTE photodetector, integrating a resonant nanophotonic structure with a photothermoelectric nanofilm. This detector capitalizes on the synergistic interactions between metasurfaces and photonic resonators, achieving an unprecedented peak absorption rate of 98.6% across a critical operational range of 8–20 μm. Our pioneering integration of the perfect absorber with photothermoelectric materials facilitates the fabrication of a self-powered detector, showcasing a responsivity of 0.388 mA W⁻¹, a rapid response time of 10 ms, and outstanding air stability. This research not only validates the feasibility of room-temperature, highly sensitive, and broadband photodetectors but also introduces a scalable approach that can be extended to other spectral regions through straightforward modifications to the resonant wavelength of the absorber.