Aluminium rods for displays

Display technologies have come a long way from the days of cathode ray tubes that used inorganic phosphors to provide lighting. Modern liquid crystal displays employ light emitting diodes or organic LEDs to handle lighting to do the job instead. However organic LEDs or OLEDs tend to be less stable and research has been looking to find inorganic display technology that works

One possible avenue of exploration has been surface plasmonics. The resonance of surface electrons from certain metals can be used to create colored light. For surface plasmonics to be employed commercially it would obviously have to supply the three primaries in the form of red, green and blue.

Gold for example can provide vibrant greens and reds through surface plasmonics but it is unable to deliver blues. Silver on the other hand can provide all three colors but is prone to oxidation. Additionally there is the fact that both these metals are rare and expensive.

A team of researchers at the Rice University in Houston, Texas however may have found a new metal that can make surface plasmonics viable. In a paper published in the Proceedings of the National Academy of Sciences, they detail how aluminium can perform the job that gold and silver have been unable to.

There have been prior attempts at building aluminium based screens. But aluminium is able to deliver blue light but unable to produce green and red. They also have a tendency to spread light out over a range of frequencies, resulting in pallid, pastel shades rather than crisp, bright ones.

The research team’s proposed solution uses tiny aluminium. Altering the length of the aluminium rods determines the colors produced. Long rods shift light towards the red end of the spectrum. Spectral spread is dealt by arranging the rods specifically to combine their individual outputs in a process known as far-field diffractive coupling.

The technology is claimed to be compatible with existing manufacturing techniques. This would pave the way for any possible industrialization in the future.