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Due to excellent electrical and optoelectronic properties, 2D transition metal dichalcogenides and their van der Waals (vdW) heterostructures have attracted great attention for broadband optoelectronics. Here, an unreported vdW PdSe2/WS2 heterostructure is developed for robust high‐performance broadband photodetection from visible to infrared optical communication band. These heterostructure devices are simply formed by direct selenization of Pd films pre‐deposited on the chemical vapor deposited monolayer WS2, followed by wet‐transfer onto device substrates with pre‐patterned electrodes. Importantly, the obtained heterostructure device exhibits an impressive broadband spectral photoresponse with response times less than 100 ms for different wavelength regions (532 to 1550 nm), where this performance is significantly better than that of pristine monolayer WS2 devices. This performance enhancement is attributed to the type I band alignment of the heterostructure. Under illumination, both intralayer and interlayer excitations are involved to generate carriers in the relevant layer, enabling the broadband photoresponse. Photocarriers would then undergo charge separation in the depletion region with electrons transferred into the charge transport layer of WS2 through the built‐in electric field, followed by the relaxation to valance band via interlayer or intralayer transition. All these findings can indicate the promising potential of vdW PdSe2/WS2 heterostructures for next‐generation high‐performance optoelectronics. [ABSTRACT FROM AUTHOR]

High‐performance flexible room‐temperature near‐infrared (NIR) photodetectors are one of the important components for image sensing, data communication, environmental monitoring, and bioimaging applications. However, there is still a lack of suitable device channel materials to provide high sensitivity as well as good mechanical flexibility for photodetection, particularly operating at the optical communication wavelength of 1550 nm. In this work, highly crystalline In0.28Ga0.72Sb nanowires (NWs) are successfully grown by the two‐step chemical vapor deposition method and assembled into high‐density regular NW parallel arrays on polyimide substrates. When they are constructed into photodetectors without using any p–n junctions, they exhibit the excellent responsivity up to 1520 A W−1 and ultra‐fast response speed below 20 µs toward 1550 nm irradiation at room temperature, which constitutes a record high performance among all flexible NIR photodetectors reported in recent literature. Notably, these flexible NW parallel‐array photodetectors also display a superior mechanical flexibility and operation durability. They not only provide a stable photoresponse under illumination on–off cycles up to 1000 s, but also maintain the steady photocurrent without any significant degradation after 700 bending cycles. All these results evidently indicate the promising potential of these crystalline In0.28Ga0.72Sb NW parallel arrays for next‐generation flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]