Room‐temperature‐operating highly sensitive mid‐wavelength infrared (MWIR) photodetectors are utilized in a large number of important applications, including night vision, communications, and optical radar. Many previous studies have demonstrated uncooled MWIR photodetectors using 2D narrow‐bandgap semiconductors. To date, most of these works have utilized atomically thin flakes, simple van der Waals (vdW) heterostructures, or atomically thin p–n junctions as absorbers, which have difficulty in meeting the requirements for state‐of‐the‐art MWIR photodetectors with a blackbody response. Here, a fully depleted self‐aligned MoS2‐BP‐MoS2 vdW heterostructure sandwiched between two electrodes is reported. This new type of photodetector exhibits competitive performance, including a high blackbody peak photoresponsivity up to 0.77 A W−1 and low noise‐equivalent power of 2.0 × 10−14 W Hz−1/2, in the MWIR region. A peak specific detectivity of 8.61 × 1010 cm Hz1/2 W−1 under blackbody radiation is achieved at room temperature in the MWIR region. Importantly, the effective detection range of the device is twice that of state‐of‐the‐art MWIR photodetectors. Furthermore, the device presents an ultrafast response of ≈4 µs both in the visible and short‐wavelength infrared bands. These results provide an ideal platform for realizing broadband and highly sensitive room‐temperature MWIR photodetectors.

Metal phosphorous tri-chalcogenides are a category of new ternary 2D layered materials with a wide range of tuneable bandgaps (1.2-3.5 eV). These wide-bandgap semiconductors exhibit great potential applications in solar-blind ultraviolet (SBUV) photodetection. However, these 2D solarblind photodetectors suffer from low photoresponsivity, slow photoresponse speed, and narrow operation spectral region, thereby limiting their practical applications. Here, an ultra-broadband photodetection based on a FePSe 3 / MoS 2 heterostructure with coverage ranging from solar-blind ultraviolet 265 nm to longwave infrared (LWIR) 10.6 µm is reported. Notably, the device exhibits excellent weak light detection capability. A high photoresponsivity of 33 600 A W −1 and an external quantum efficiency of 1.57 × 10 7 % are demonstrated. A noise-equivalent power as low as 5.7 × 10 -16 W Hz −1/2 and a specific detectivity up to 1.51 × 10 13 cm Hz 1/2 W −1 are realized in the SBUV region. The room temperature LWIR photoresponsivity of 0.12 A W −1 is realized. This work opens a route to design high-performance SBUV photo detectors and wide spectral photoresponse applications.

The discovery of 2D ferromagnetic (FM) van der Waals (vdW) semiconductors with narrow bandgap and p‐type transport behavior makes them promising for infrared photodetection. Here, a 2D vdW heterodiode uncooled long‐wave infrared (LWIR) photodetector by stacking a p‐type 2D FM material CrSiTe3 on top of an n‐type transition metal dichalcogenides (TMDs) MoS2 is reported. A good rectification ratio >102 and an ultra‐broadband photoresponse from 0.52 to 10.6 μm are demonstrated. The photoresponsivity of up to 20.7 A W−1 and the external quantum efficiency (EQE) of up to 4031.7% are obtained under a 1310 nm laser at a −1 V bias in ambient, which indicates that these CrSiTe3–MoS2 p–n junction devices have a good photovoltaic response. Meanwhile, the photovoltaic responsivity up to 0.15 A W−1, EQE up to 29.7%, and fast response with a decay time of 2.8 μs at 637 nm are demonstrated. In addition, the room temperature mid‐wave infrared (MWIR) specific detectivity and LWIR specific detectivity of CrSiTe3–MoS2 is 6.1 × 109 cm Hz1/2 W−1 and 1.93 × 109 cm Hz1/2 W−1, respectively. These observations open up possibilities for developing high‐sensitive infrared detection based on the valley optical selection rule and LWIR image technology.

The excessive growth of carbon emissions (CO2E) from industrial energy use not only exacerbates global warming and severely curbs the sustainable development of the economy and society. As a high energy-consuming sector second only to the fossil energy division, the power and heavy division, China's chemical industry should have received more attention for its CO2E. However, there are limited literatures on energy CO2E in China's chemical sector at present. Based on this fact, this current paper uses the energy utilization approach, the input–output analysis approach, and the extended structural decomposition method to evaluate the energy-related CO2E of China's chemical sector from 2007 to 2017. (1) China's chemical sector energy-related CO2E showed a trend of first growth and then a slow decline, demonstrating that the rapid growth of China's chemical sector energy-related CO2E has been effectively controlled; However, it should be noted that the chemical industry is still dominated by high-CO2E energy-related CO2E at the current stage. (2) Input structure and energy intensity effects have a reduced influence on the growth of energy-related CO2E in China's chemical sector. This is due to upgrading energy use technology and optimizing the generalized technology progress rate in the chemical sector. (3) Energy structure and final demand effects have encouraged the growth of the chemical sector's energy-related CO2E. It shows that the industrial system's demand for chemical products is constantly expanding, and the chemical products still have the characteristics of high carbonization. Also, the chemical sector's supply-side energy utilization structure has not been significantly enhanced.

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