nanofios

Nanofios, or nanowires in English, are nanoscale one-dimensional structures with diameters typically in the 1-100 nanometer range and lengths that can extend to several micrometers or more. Their high aspect ratio, crystallinity, and large surface-to-volume ratio give rise to distinctive electrical, optical, and mechanical properties suitable for nanoscale devices.

Nanofios can be produced by top-down approaches, such as lithography and etching of bulk materials, or bottom-up methods that assemble atoms or molecules into wires. Bottom-up methods include vapor-liquid-solid growth for semiconductor nanowires, solvothermal and solution-phase synthesis, electrochemical deposition in templates, and template-assisted electrospinning. Materials include metals (gold, silver, copper), semiconductors (silicon, GaN, ZnO, InP, CdSe), and oxide nanowires (TiO2, SnO2).

Key properties depend on material and diameter. Quantum confinement and surface states can affect carrier transport, optical absorption, and band gaps. Nanofios often exhibit excellent electrical conductivity for metals, or high on/off current ratios for semiconductors, and can act as waveguides or plasmonic elements at nanoscale.

Applications span nanoelectronics, sensors, photonics, energy conversion and storage, catalysis, and biomedicine. Integrated nanowire arrays can function as transistors, photodetectors, or solar-cell elements; single nanowires serve as sensitive chemical or biological sensors; and networks enable flexible energy devices and catalytic electrodes.

Challenges include achieving uniform diameters and lengths, reducing defects and impurities, controlling growth orientation, and integrating nanofios with conventional fabrication processes. Ongoing research focuses on aligned growth, core-shell and heterostructure nanowires, and scalable synthesis for commercial devices.