Broadband MoS₂ Square Nanotube-Based Photodetectors

Although the research on layered MoS2 photodetectors has made great progress, their poor light absorption ability and complex preparation process hinder their further commercial application. In the present work, we report the growth of MoS2 square nanotubes with high purity via a facile hydrothermal method for the first time. Microstructure characterization demonstrates that the cavity structure of the nanotubes can bring about a light trapping effect, thus obtaining a strong photoelectric performance. The as-constructed MoS2 square nanotube photodetector with a paper substrate displays a broadband response with a detection range of 375 to 915 nm. It exhibits excellent performance with a high responsivity of 2.33 mA/W under 915 nm light irradiation, which is comparable to the best ones ever reported for polycrystalline MoS2 photodetectors

Thermal Stability of Skyrmion Tubes in Nanostructured Cuboids

Magnetic skyrmions in bulk materials are typically regarded as two-dimensional structures. However, they also exhibit three-dimensional configurations, known as skyrmion tubes, that elongate and extend in-depth. Understanding the configurations and stabilization mechanism of skyrmion tubes is crucial for the development of advanced spintronic devices. However, the generation and annihilation of skyrmion tubes in confined geometries are still rarely reported. Here, we present direct imaging of skyrmion tubes in nanostructured cuboids of a chiral magnet FeGe using Lorentz transmission electron microscopy (TEM), while applying an in-plane magnetic field. It is observed that skyrmion tubes stabilize in a narrow field-temperature region near the Curie temperature (Tc). Through a field cooling process, metastable skyrmion tubes can exist in a larger region of the field-temperature diagram. Combining these experimental findings with micromagnetic simulations, we attribute these phenomena to energy differences and thermal fluctuations. Our results could promote topological spintronic devices based on skyrmion tubes