Nanoscale device converts wasted light into energy

UNSW Sydney scientists have addressed a longstanding problem in photonics: how to stop energy from being lost before it can be used.

The researchers managed to create a nanoscale device that converts low-energy infrared and red light into higher-energy visible light. The device achieved photon conversion efficiencies of 8.2% — among the strongest reported for this type of architecture, according to UNSW.

“This work demonstrates a big step forward,” said the study’s lead author, UNSW researcher Dr Thilini Ishwara.

“Achieving high efficiencies in films is difficult in these ultrathin molecular systems — good light absorption is needed and energy loss needs to be minimised.”

The breakthrough has implications for industries looking to recover or reuse wasted infrared light, such as solar panel manufacturing. In solar energy systems, large amounts of low-energy light pass straight through conventional silicon cells unused; converting some of that light into visible wavelengths could improve overall performance.

The researchers said the approach may also be relevant to infrared sensing, photocatalysis, optical communications and next-generation additive manufacturing technologies such as volumetric 3D printing.

Importantly, the system operates in a solid-state structure compatible with semiconductor-style manufacturing, making it more commercially practical than earlier liquid-based approaches.

“We are keen to commercialise our technology,” Ishwara said.

“It could be used for a range of techniques such as tumour treatment with deeper tissue penetration, cheap water purification, night vision and 3D printing.”

The study has been published in Nature Photonics.

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