Growing high-quality core-shell heterostructure nanowires is still challenging due to the lattice mismatch issue at the radial interface. Herein, a versatile strategy is exploited for the lattice-mismatch-free construction of III-V/chalcogenide core-shell heterostructure nanowires by simply utilizing the surfactant and amorphous natures of chalcogenide semiconductors. Specifically, a variety of III-V/chalcogenide core-shell heterostructure nanowires are successfully constructed with controlled shell thicknesses, compositions, and smooth surfaces. Due to the conformal properties of obtained heterostructure nanowires, the wavelength-dependent bi-directional photoresponse and visible light-assisted infrared photodetection are realized in the type-I GaSb/GeS core-shell heterostructure nanowires. Also, the enhanced infrared photodetection is found in the type-II InGaAs/GeS core-shell heterostructure nanowires compared with the pristine InGaAs nanowires, in which both responsivity and detectivity are improved by more than 2 orders of magnitude. Evidently, this work paves the way for the lattice-mismatch-free construction of core-shell heterostructure nanowires by chemical vapor deposition for next-generation high-performance nanowire optoelectronics.

Bio-chemical molecular detection in the nanoscale, based on alloyed nanorods (NRs) with tunable surface plasmon resonance (SPR) properties and high chemical stability, has attracted particular interest. In this work, alloyed Au-Ag NRs with tunable aspect ratios were achieved by annealing Au nanobipyramid-directed Au@Ag core-shell NRs. The core-shell NRs were encapsulated within mesoporous silica outer shells to avoid fusion or aggregation. The structural stability of fully alloyed Au-Ag NRs, including chemical and thermal stability, is remarkably improved compared with that of Au@Ag core-shell NRs. The alloyed NRs would maintain the rod-like structure after being incubated in etchant solution, while Au@Ag core-shell NRs would decay into nanobipyramids. Additionally, fully alloyed NRs present stable morphology under annealing at high temperatures of up to 600°C in air. Benefiting from excellent structural and chemical stabilities, the surface-enhanced Raman scattering effect based on alloyed NRs is stable in harsh environments. Taking advantage of tunable SPR properties (600–1800 nm) and excellent stability, the obtained nanostructures can serve as drug carriers. The perfect photo-thermal effect induced by the particular SPR of alloyed NRs can improve the release efficiency of drugs.