Flexible Self-Powered Short-Wave Infrared Image Sensors Enabled by Te0.62Se0.38/MoS2 Heterojunctions

Flexible short-wave infrared (SWIR) photodetectors are critical for versatile emerging applications, including wearable health monitors, artificial vision, and curved-surface imaging systems. Nevertheless, conventional SWIR photodetectors struggle to achieve mechanical flexibility due to their intrinsic rigidity and high-temperature processing requirements. Herein, we report flexible, self-powered SWIR image sensors based on Te0.62Se0.38/MoS2 heterojunctions. Their staggered type-II band alignments facilitate efficient photocarrier separation, demonstrating a broadband photoresponse extending to a cut-off wavelength of 1700 nm, a linear dynamic range of over 80 dB, an exceptional photo-to-dark current ratio exceeding 105, and a room-temperature specific detectivity of 1.8×109 Jones for 1550 nm illumination. Benefiting from these superior optoelectronic properties, self-powered SWIR single-pixel imaging and optical communication applications were realized. Furthermore, taking advantage of the unique one-dimensional helical chain structure of the Te-Se alloy and the ultrathin nature of MoS2, heterojunction devices fabricated on flexible polyimide substrates exhibit outstanding mechanical endurance, retaining their initial response even at a bending radius of 4 mm. These findings highlight the considerable potential of Te-Se/MoS2 heterojunctions as a versatile material platform for flexible SWIR optoelectronics and provide a promising avenue toward next-generation wearable and intelligent sensing systems.