Based on a proposed novel electronicstructure strategy, layered MoS2 is designed, which realizes ultrabroadband photodetection at room temperature. By introducing defect energy levels, the bandgap and electronic state density are modulated suitably. The prototype photodetector is investigated from 445 nm (blue) to 9536 nm (far‐IR) and offers a record high photoresponsivity of 21.8 mA W−1 (7.79 µm). Abstract Photodetection using semiconductors is critical for capture, identification, and processing of optical information. Nowadays, broadband photodetection is limited by the underdeveloped mid‐IR photodetection at room temperature (RT), primarily as a result of the large dark currents unavoidably generated by the Fermi–Dirac distribution in narrow‐bandgap semiconductors, which constrains the development of some modern technologies and systems. Here, an electronic‐structure strategy is proposed for designing ultrabroadband covering mid‐ and even far‐IR photodetection materials operating at RT and a layered MoS2 is manifested with an engineered bandgap of 0.13 eV and modulated electronic state density. The sample is designed by introducing defect energy levels into layered MoS2 and its RT photodetection is demonstrated for wavelengths from 445 nm to 9.5 µm with an electronic state density‐dependent peak photoresponsivity of 21.8 mA W−1 in the mid‐IR region, the highest value among all known photodetectors. This material should be a promising candidate for modern optoelectronic devices and offers inspiration for the design of other optoelectronic materials.
Published in: "Advanced Materials".