Scientists develop printable lasers

Printing your own solar panels or TV screens could be as easy as popping to the local newsagent for some laser ink.
By Rebecca Baker July 1, 2010 Reading Time: 2 Minutes

AUSTRALIAN AND ITALIAN SCIENTISTS have created a nano-crystal ink that could be used to print cheap TV screens, lights and solar panels.

CSIRO scientist Dr Jacek Jasieniak and colleagues from the University of Melbourne and the University of Padua in Italy developed the inks from semi-conducting crystals called quantum dots, which are about a millionth of a millimetre in diameter.

When the quantum dots are printed in a certain way onto a surface they transform into millions of tiny lasers, which are “highly efficient and can be adapted for numerous applications,” Jacek says.

The laser technology has the potential to revolutionise associated industries because of its low production costs, Jacek says. “At present, lasers are manufactured using expensive materials and production techniques, but because these lasers can be printed, this affords roll-to-roll processing, which directly translates to faster and cheaper production.”

This technology will allow for printing over large areas and on materials such as glass or plastic. Scientists hope to use these lasers for lighting in homes, electronics, and laser pointers; they could even act as pixels in printable TV screens for an ultra-thin screen.

Available in the “near future”

The mini lasers emanate their own light, making them very efficient and environmentally friendly. The quantum dots need a kick start by another light source once they’re inside an ‘optical cavity’ created in the printing process.

The laser colour produced by the quantum dots can be changed by varying their size; certain crystals can produce colours that span the entire visible spectrum, from red right through to blue.

The scientists have already developed prototype lasers and predict that we could be seeing this type of technology in our own homes in the “near future”, which would likely be within the decade, Jacek says, but this depends on the research progress and commercial interest.

The research for the new technology was presented this week at the Fresh Science conference, a program sponsored by the Federal Government to promote young scientists doing interesting work.

Head of Semiconductor Optoelectronics and Nanotechnology Group at the Australian National University, Professor Chennupati Jagadish, says that further research needs to be done to really see how viable these technologies can become.

“Writing a paper and demonstrating these things is one thing, but translating that into commercial technologies is a major challenge,” Chennupati says. “It’s interesting and if we can keep an open mind we can hope that it will lead to innovative and commercially viable applications.”

Associate professor in photonics at the University of New South Wales Francois Ladouceur says the study raises more questions than answers but any improvement on laser technologies can be beneficial.

“Essentially, any means of providing laser light cheaply and conveniently – as in, better than it is done now – is a good and significant advance,” he says.