Australian solar pioneers win world's top engineering prize

Four Australian solar researchers have been awarded the 2023 Queen Elizabeth Prize for Engineering (QEPrize). The group was recognised for its pioneering work at UNSW Sydney to develop Passivated Emitter and Rear Cell (PERC) solar photovoltaic technology, which has underpinned the recent exponential growth in high performance, low-cost solar electricity.

The Prize, which has been called the ‘Nobel for engineering’, is presented annually to engineers responsible for ground-breaking innovations that have been of global benefit to humanity. It is regarded as one of the world’s top academic awards rated by the IREG List of International Academic Awards and has a reputation score of 0.51 compared to a Nobel Prize. Sharing the 2023 Prize are Professor Martin Green from UNSW Sydney, Professor Andrew Blakers from the Australian National University and solar entrepreneurs Dr Aihua Wang and Dr Jianhua Zhao. 

Celebrating its 10^th year in 2023, the Prize announcement was made in London by Lord Browne of Madingley, Chairman of the QEPrize Foundation. Lord Browne said: “The QEPrize celebrates the engineers who time and time again solve the impossible and transform our world for the better. I believe that everything we do has to be oriented around the global energy transition so we can achieve net zero, for the planet and the people that live on it. PERC solar cell technology has been and will continue to be integral to this journey. I wholeheartedly congratulate Professors Green and Blakers, and Drs Wang and Zhao for their contribution to humanity.”

Read more: UNSW Sydney solar pioneer wins Europe's biggest technology innovation prize

The 2023 Laureates greatly improved the energy conversion efficiency of commercially dominant silicon cells, by improving the quality of both the top and the rear surface of standard silicon solar cells.

When sunlight – in the form of particles called photons – enters a cell, it excites the electrons within the silicon. In this excited state, electrons can move through the cell, creating electric current. The improved surface of the PERC cell allows the electrons to maintain this excited state – or move freely – for longer, resulting in greater and more efficient energy generation.

Dr Jianhua Zhao, Professor Martin Green, Dr Aihua Wang. Photo: UNSW Sydney

Profs Green and Blakers produced solar cells with 18 per cent efficiency at UNSW in 1983, surpassing the 16.5 per cent recorded previously. Over the next two years, Profs Green and Blakers published cell results of 19 per cent and 20 per cent efficiency, subsequently achieving over 21 per cent efficiency in 1989 with Drs Wang and Zhao. Prof. Green theoretically determined the maximum achievable efficiency to be close to 30 per cent. He suggested the maximum practical limit of 25 per cent efficiency, with Drs Wang and Zhao leading the work which ultimately reached this goal in 1999.

Prof. Green’s lab at UNSW held the global record for efficiency for 30 of the 40 years between 1983 and 2023.

Prof. Green said he was honoured to share the QEPrize with his three former PhD students, Prof. Blakers and Drs Wang and Zhao. “As engineers, we are constantly striving to improve the world we live in. As the world feels the devastating impacts of our changing environment and collapsing ecosystems, I feel passionately that we must rapidly reduce our reliance on fossil fuels if we wish to maintain the trajectory of human civilisation on our shared planet. I hope that PERC technology winning the QEPrize will highlight the importance of accelerated solar adoption to address climate change.”

Prof. Blakers said: "This is such an honour for me, and indirectly for the many wonderful people I have worked with over many years. I am delighted to share this prize with Martin Green and Drs Wang and Zhao, who have made major contributions to solar energy over many decades."

Driving down the costs of solar

Recognising the significant role PERC technology plays in the development of solar energy, the awardees published their findings without patenting, encouraging further developments within the field and driving down the cost of production to the benefit of wider society.

Prof. Green said he was proud of the major impact the achievements of many of his former students, including his fellow awardees, have had on the world. “This has not only been in developing new cell technologies like PERC, but also in transforming the solar manufacturing industry by using their expertise to establish manufacturing in low-cost regions of Asia. This is one of the main reasons that solar has suddenly become so cheap over the last decade,” Prof. Green said.

Drs Wang and Zhao set up China’s second large-scale solar manufacturer, China Sunergy, in 2006, after a combined 40 years at UNSW. The first (Suntech) was established by another one of Prof. Green’s proteges, Zhengrong Shi.

With the cost of solar power generation falling by over 80 per cent in the past decade, PERC technology is now the most commercially viable silicon solar cell technology used in solar panels and large-scale electricity production.  It accounts for almost 90 per cent of the global solar cell market. 

ANU Professor Andrew Blakers. Photo: Jamie Kidston/ANU.

Prof. Blakers said he hoped to use his new-found platform as a QEPrize recipient to highlight the importance of accelerated solar adoption to address the threat of global warming. “Solar energy is enormously abundant nearly everywhere. Silicon solar cells allow clean and affordable electrification of energy-poor rural areas across Asia, Africa and the Americas.”

Australia is the global solar pathfinder and is generating about twice as much solar energy per person compared to any other country. Together, solar and wind are rapidly displacing coal and gas from the national electricity grid.

“Silicon solar cells provide the cheapest energy source in history. Universal access to very cheap and abundant solar and wind energy allows the elimination of fossil fuels, resulting in an 80 per cent reduction in global greenhouse emissions,” Prof. Blakers said.

The QEPrize Laureates will share £500,000 in prize money and will be honoured at a presentation ceremony in London later this year.

Find out more about the QEPrize for Engineering and this year's winning innovations.