Centre of Excellence giving solar energy a twist

Research into solar cell technology at different nodes of the ARC Centre of Excellence in Exciton Science is leading to a number of novel technologies and methods with commercialisable outcomes.

The ARC Centre of Excellence in Exciton Science (Exciton Science) has several research teams working at different Australian universities with international partners looking into possibilities for transforming light into energy – and energy into light – for innovative renewable energy solutions, including solar technology, energy efficient lighting and security systems.

One Exciton Science research project, featuring Elham Gholizadeh as lead researcher and supervised by Chief Investigator Tim Schmidt at The University of New South Wales (UNSW), has made a breakthrough in light conversion that could potentially impact solar photovoltaics, biomedical imaging, drug delivery and photocatalysis. The team has been able to ‘upconvert’ low energy light into high energy light, which can be captured by solar cells, in a new way.

Most solar cells are made from silicon, which restricts the range of light that can be absorbed. This means that some parts of the light spectrum are going unused by many
current devices and technologies.

To extend the sensitivity range of these devices, the team has turned low energy light into more energetic, visible light that can be absorbed by silicon.

Contributing researcher Professor Jared Cole from RMIT University says that using oxygen to transfer energy is a breakthrough that goes against the grain for that particular atom.

‘Often without oxygen, upconversion works well enough. However, as soon as you allow oxygen in, the process stops working,’ Jared said. ‘It was the Achilles heel that ruined all our plans, but now, not only have we found a way around it, suddenly it helps us.’

Meanwhile, at the Monash University-based team at Exciton Science, researchers are adapting solar energy technology in a different way. The team has adapted a technology that’s being used to improve solar power – synthetic nanocrystals based on a perovskite structure – and turned it into a detection method.

‘Perovskite nanocrystals have proved to be a very efficient light emitter,’ says lead researcher DrWenping Yin.

The researchers discovered that perovskites change colour within seconds of coming into contact with a common, although toxic, agricultural fumigant, which could previously only be detected using expensive laboratory instrumentation with long delays.

‘The underlying detection method can be readily expanded to detect a range of other pesticides and chemical warfare agents,’ says senior research leader Professor Jacek Jasieniak, at Monash University.

The next steps are to work with industry partners at Australia’s national science agency CSIRO and the Department of Defence to develop the technology for use by defence force personnel and first responders.