Aalto University researchers have come up with a novel process of fabricating carbon nanotube thin films, enabling them to display a variety of different colors.
Single-walled carbon nanotubes have found many uses in electronics and new touch screen devices. However by nature, carbon nanotubes are typically black or a dark grey.
Now Aalto researchers have used a fine-tuned fabrication process – and a small dose of CO2 – to produce large quantities of pristine single-walled carbon nanotubes in select shades of the rainbow.
The researchers believe this is the first time that colored carbon nanotubes have been produced by direct synthesis.
The color is induced straight away in the fabrication process, and not by employing a range of purifying techniques on finished, synthesized tubes.
With direct synthesis, large quantities of clean sample materials can be produced while also avoiding damage to the product in the purifying process – which makes it the most attractive approach for applications.
‘In theory, these colored thin films could be used to make touch screens with many different colours, or solar cells that display completely new types of optical properties,’ says Aalto professor Esko Kauppinen.
To get carbon structures to display colors is a feat in itself. The underlying techniques needed to enable the coloration also imply finely detailed control of the structure of the nanotube structures.
Kauppinen and his team’s unique method, which uses aerosols of metal and carbon, allows them to carefully manipulate and control the nanotube structure directly from the fabrication process.
According to the researchers, the method developed by them promises a simple and highly scalable way to fabricate carbon nanotube thin films in high yields.
Image and content credits: Aalto University