Nanowires are fantastic nanostructures for designing new functional devices because of their extraordinary properties. However, nanowires usually suffer pronounced size and surface effects with decreasing diameter size. Whether their structure and thermal stability can still fill the requirements of practical applications is a critical issue to be figured out. Herein, Te nanowires with diameters ranging from sub-10 to over 80 nm are used as samples to probe into this issue. In situ heating experiments are performed on these Te nanowires using an aberration-corrected transmission electron microscopy combined with a chip-based heating holder. It is found that Te nanowires suffer sublimation at elevated temperatures rather than melting, showing size-dependent sublimation scenarios. The Te nanowires with diameter smaller than 20 nm sublimate below 205 °C, while the larger ones with diameter around 85 nm require a higher temperature of around 225 °C. During sublimation-induced shape evolution, the interfacial wetting equilibrium and crystal orientations play critical roles, leading to the formation of spherical surfaces or featured facets at the free surfaces. A mean contact angle of 107.5° is determined at the C–Te interface when the crystalline Te nanowires stay in a quasi-liquid equilibrium state. However, once the crystalline feature is overwhelming, e.g., at moderate temperatures, the ( $10\overline{1}1$), ( $11\overline{\text{2}}0$), and ( $10\overline{\text{1}}0$) facets govern the free surface, despite the wetting condition at the interfaces.

As one of the most important narrow bandgap ternary semiconductors, GaAs_1-xSb_x nanowires (NWs) have attracted extensive attention recently, due to the superior hole mobility and the tunable bandgap, which covers the whole near-infrared (NIR) region, for technological applications in next-generation high-performance electronics and NIR photodetection. However, it is still a challenge to the synthesis of high-quality GaAs_1-xSb_x NWs across the entire range of composition, resulting in the lack of correlation investigation among stoichiometry, microstructure, electronics, and NIR photodetection. Here, we demonstrate the success growth of high-quality GaAs_1-xSb_x NWs with full composition range by adopting a simple and low-cost surfactant-assisted solid source chemical vapor deposition method. All of the as-prepared NWs are uniform, smooth, and straight, without any phase segregation in all stoichiometric compositions. The lattice constants of each NW composition have been well correlated with the chemical stoichiometry and confirmed by high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectrum. Moreover, with the increase of Sb concentration, the hole mobility of the as-fabricated field-effect-transistors and the responsivity and detectivity of the as-fabricated NIR photodetectors increase accordingly. All the results suggest a careful stoichiometric design is required for achieving optimal NW device performances.