Researchers have created a molybdenum disulfide/graphene/mercury cadmium telluride (MoS2/graphene/MCT) photodetector that achieves an order-of-magnitude improvement in specific detectivity across both visible and mid-wavelength infrared ranges. The device addresses a longstanding challenge in room-temperature mid-wavelength infrared detection: excessive dark current, typically caused by defects in complex multilayer structures. This new van der Waals heterostructure induces “a strong built-in electric field and potential barrier” to suppress dark current, while graphene minimizes trap-assisted recombination. MoS2/Graphene/MCT Heterostructure Enables Uncooled Mid-Infrared Detection The device addresses persistent challenges in room-temperature mid-wavelength infrared detection by suppressing dark current and interfacial recombination, critical factors limiting performance in uncooled sensors. Researchers designed a tri-layered van der Waals heterostructure to achieve this synergistic effect, combining interface band alignment engineering with defect passivation strategies. The core of the innovation lies in the type-II band alignment formed at the MoS2/MCT junction, enabling efficient separation of photogenerated carriers through a built-in electric field. Under illumination, minority electrons within the MCT layer are directed to the MoS2 layer with graphene acting as an assisting interlayer, maximizing photocurrent generation. Simultaneously, a substantial interfacial barrier blocks majority holes, significantly reducing dark current and improving signal clarity. The optimized device demonstrates a responsivity of ~0.325 A W−1 and a peak detectivity of ~8 × 10^10 cm Hz^1/2 W−1 under room-temperature blackbody radiation, outperforming uncooled MWIR photodetectors. “The incorporation of graphene into the 2D/MCT vdW heterostructure synergistically blocked dark current and suppressed interfacial recombination,” leading to extended carrier lifetime and efficient interlayer charge transfer, according to the study. The resulting architecture represents a step toward practical, uncooled mid-infrared detection systems. Dark Current Limitation in Traditional MCT Photodetectors Mercury cadmium telluride (MCT) has long been the material of choice for mid-wavelength infrared (MWIR) detection, but practical applications have been hampered by a persistent obstacle: dark current. Traditional MCT photodetectors