A little impurity makes nanolasers shine

Monday 4 July 2016 10am

Scientists at The Australian National University (ANU) have improved the performance of tiny lasers by adding impurities, in a discovery which will be central to the development of low-cost biomedical sensors, quantum computing, and a faster internet.

Researcher Tim Burgess added atoms of zinc to lasers one hundredth the diameter of a human hair and made of gallium arsenide – a material used extensively in smartphones and other electronic devices.

The impurities led to a 100 times improvement in the amount of light from the lasers.

“Normally you wouldn’t even bother looking for light from nanocrystals of gallium arsenide – we were initially adding zinc simply to improve the electrical conductivity,” said Mr Burgess, a PhD student in the ANU Research School of Physics and Engineering.

“It was only when I happened to check for light emission that I realised we were onto something.”

Gallium arsenide is a common material used in photovoltaic cells, lasers and light-emitting diodes (LEDs), but is challenging to work with at the nanoscale as the material requires a surface coating before it will produce light.

Previous ANU studies have shown how to fabricate suitable coatings.

The new result complements these successes by increasing the amount of light generated inside the nanostructure, said research group leader Professor Chennupati Jagadish, from the ANU Research School of Physics Sciences.

“It is an exciting discovery and opens up opportunities to study other nanostructures with enhanced light emission efficiency so that we can shrink the size of the lasers further,” he said.

Mr Burgess said that the addition of the impurity to gallium arsenide, a process called doping, did not only improve the light emission.

“The doped gallium arsenide has a very short carrier lifetime of only a few picoseconds, which meant it would be well suited to use in high speed electronics components,” he said.

“The doping has really has given these nanolasers a performance edge.”

The research is published in Nature Communications.

Contact

Professor Chennupati Jagadish
E: Chennupati.Jagadish@anu.edu.au
T: (02)61250363

Related news stories

Imagine a laser toothbrush: scientists create array of nanowire lasers

Scientists have created lasers from perfect crystals one hundredth of the diameter of a human hair. Like the fibres of a toothbrush, the team created an array of vertical crystals, termed nanowires, on a platform, and succeeded in making them simultaneously emit laser light for the first time. Dr Fanlu...

Quantum dot glowsticks could light up future technology

The heart of future quantum devices could be lit up by arrays of tiny glow-sticks, developed by ANU physicists. A group from the Department of Electronic Materials Engineering (EME) manufactured an array of tens of thousands of indium phosphide nanowires and made them glow by incorporating single quantum...

Pressure makes nanodiamonds, or nanopyramids, or nanowires

Holograms made from arrays of tiny wires are a step closer after a new study of nanostructure fabrication revealed the tricks to making nanowires reliably. Physicists at the Australian National University node of TMOS studied growth of gallium nitride nanostructures by chemical vapour techniques and found...

Optical counterparts of diodes could spur new area of technology

The inventors of nano-isolators – the optical equivalent of a diode – say the device could start a technology revolution. In the 1950s, a technological revolution in electronics began, spurred by the miniaturization of diodes and transistors. The first electronic devices, simple radios and TVs,...