Nanofiber

--Mithlesh K.Bhagat,Pramod Singh,Rakesh Dhull,Rajeev Jaiswal)

In this paper we are summarizing the past, present and future of fabrication of nanofibers and nanowires. Some of already explored applications of these are in electronic devices e.g. Field-effect transistors, sensors, detectors and light-emitting diodes etc. and many new are coming up. Semiconductor nanowires are one-dimensional structures, with unique electrical and optical properties e.g. Quantum confinement effects. Fabrication at nanoscale and at low temperature with lot of other constraints is a promising area of research.

The vapor liquid solid (VLS) process is a fundamental mechanism for the growth of nanowires. In this process a small size (5 -100 nm in diameter), high melting point metal (such as Gold and Iron) catalyst particle directs the nanowires growth-direction. It also determines the diameter of the crystalline nanowires. The silica nanowires tend to grow batch by batch. For each batch, numerous

Highly aligned and closely packed SiO2 nanowires bunches were synthesized in a high yield by using molten Ga as a catalyst and Si wafers as Si-source via a VLS process. The use of Ga provides opportunities for the development of low temperature VLS routes for nanowires synthesis. By using Ge as a catalyst, carbon nanotubes and GeO2 nanowires can be synthesized at temperature below 800 ˚C.

nanowires simultaneously nucleate, and they grow nearly at the same rate and in the same direction, and simultaneously stop growing.

Projection electron-beam lithography in particular, appears to be promising because (i) It relies on electron, whose usefulness generating masters with features well below 100 nm is inarguable, and (ii) It uses projection optics, which allows features in the replicas to be much smaller( ~ 4 times) then those on the mask.

By using a two step drawing process, one can fabricate long free standing silica wires with diameters down to 50 nm .It has surface smoothness at atomic level as well as uniformity of diameter. Light can be launched into these wires

Some topics in this essay:
SiO Si, Gold Iron, DhullRajeev Jaiswal, DA- IICTGandhinagarIndia-382009, below 100 nm, vls process, nm using, 100 nm, low temperature, below 100, batch batch, thermal evaporation,