Spectrally\nTunable Ultrafast Long Wave Infrared Detection\nat Room Temperature

Room-temperature longwave infrared (LWIR) detectors are\npreferred\nover cryogenically cooled solutions due to the cost effectiveness\nand ease of operation. The performance of present uncooled LWIR detectors\nsuch as microbolometers, is limited by reduced sensitivity, slow response\ntime, and the lack of dynamic spectral tunability. Here, we present\na graphene-based efficient room-temperature LWIR detector with high\ndetectivity and fast response time utilizing its tunable optical and\nelectronic characteristics. The inherent weak light absorption is\nenhanced by Dirac plasmons on the patterned graphene coupled to an\noptical cavity. The absorbed energy is converted into photovoltage\nby the Seebeck effect with an asymmetric carrier generation environment.\nFurther, dynamic spectral tunability in the 8–12 μm LWIR\nband is achieved by electrostatic gating. The proposed detection platform\npaves the path to a fresh generation of uncooled graphene-based LWIR\nphotodetectors for wide ranging applications such as molecular sensing,\nmedical diagnostics, military, security and space.