High-Sensitive Uncooled Mid-Wave Infrared Detector Based on TiS₃ Nanoribbon

High-sensitive uncooled mid-wave infrared (MWIR) photodetection with fast speed is highly desired for biomedical imaging, optical communication, and night vision technology. Low-dimensional materials with low dark current and broadband photoresponse hold great promise for use in MWIR detection. Here, this study reports a high-performance MWIR photodetector based on a titanium trisulfide (TiS₃) nanoribbon. This device demonstrates an ultra-broadband photoresponse ranging from the visible spectrum to the MWIR spectrum (405-4275 nm). In the MWIR spectral range, the photodetector achieves competitive high photoresponsivity (R) of 21.1 A W^-1, and an impressive specific detectivity (D*) of 5.9 × 10¹⁰ cmHz^1/2 W^-1 in ambient air. Remarkably, the photoresponse speed in the MWIR with τ_r = 1.3 ms and τ_d = 1.5 ms is realized which is much faster than the thermal time constant of 15 ms. These findings pave the way for highly sensitive, room-temperature MWIR photodetectors with exceptionally fast response speed.