Highly sensitive SWCNT-based pyroelectric phototransistors for broadband room temperature infrared detection

Thermal infrared (IR) detectors represent a crucial technology for various applications, yet achieving high performance without cooling remains challenging. Here, we demonstrate high-performance broadband IR photodetectors by integrating single-walled carbon nanotubes (SWCNTs) with a ferroelectric substrate, leveraging the pyroelectric effect for enhanced photodetection. Using aerosol chemical vapor deposition and capillary transfer techniques, we fabricate sparse SWCNT films on z-cut LiNbO₃ surfaces to create pyroelectrically gated field-effect transistors. The devices exhibit remarkable responsivity across the IR spectrum, with semiconducting channels achieving maximum relative responsivities reaching nearly 100 %/μW at 1550 nm. Our optimized SWCNT networks demonstrate exceptional specific detectivities of 1.7 × 10¹⁰ cm \sqrt\mathrmHz/\mathrmW at 1550 nm and 1.4 × 10¹⁰ cm \sqrt\mathrmHz/\mathrmW at 9.3 μm, surpassing graphene-based alternatives by several orders of magnitude and approaching theoretical limits. These results establish SWCNT-based pyroelectric photodetectors as promising candidates for room-temperature IR detection, eliminating the conventional requirement for cooling.