Gold nanowires fabricated by chemical method.

Aim

The aim of this project is to fabricate gold nanowires by a chemical method and characterize them in terms of size and diameters by scanning electron microscope and measure the photoluminescence of these wires using confocal microscopy.

Background

Gold nanowires with  defined crystallographic structures could serve as a model system for studies like plasmonics waveguides and tip enhanced Raman spectroscopy. Various methods are reported so far on the fabrication of metallic (silver, gold and copper) nanowires, both lithographically and chemically. The chemically fabricated metallic nanowires are monocrystalline in nature while on the other hand the wires grown by lithography leads to polycrystalline wires. The monocrystalline wires have low losses compared to polycrystalline, thus highlighting the importance and interest in chemically grown nanowires.

Fabrication

A three step seeding approach will be taken to fabricate gold nanowires. First initial gold seed particles will be made by rapid reduction of gold precursor with strong reducing agent. The growth solution will be prepared and later acid and initial seeds will be added to the growth solution in three steps, leading to the formation of gold nanowires.

Characterization

The nanowires formed will be spin coated on a silicon wafer and characterized for length and diameter by scanning electron microscope (SEM). The photoluminescence of the gold wires will be measured by a home built optical confocal microscope. The photoluminescence spectrum of the chemically grown nanowires will then be compared to the photoluminescence spectrum of lithographically grown gold nanowires.