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The 2022 Millennium Technology Prize has been awarded to Scientia Professor Martin Green of the UNSW Sydney, Australia, for his innovation that has transformed the production of solar energy. Aalto University Professor Päivi Törmä is the Chair of the International Selection Committee of the Prize.

The €1 million global award for technology, conferred every two years, recognised Green’s leadership in the developmentof the Passivated Emitter and Rear Cell (PERC). Since its development in 1983, the PERC has gone on to become the most commercially viable and efficient silicon solar cell technology for use in solar panels and for large-scale electricity production, accounting for almost 90% of the global solar cell market. 

Green developed the PERC with his team by improving the quality of both the top and the rear surface of standard silicon solar cells. The PERC has helped increase the conversion efficiency of standard solar cells by over 50% in relative terms from 16.5% in the early 1980s to 25% in the early 2000s.

The innovation has increased the efficiency of the panels without significantly increasing the manufacturing costs. The innovation has greatly reduced the costs of using solar panels, making solar energy more affordable than fossil-based alternatives. PERCs can also provide an energy supply to homes without them needing to be connected to a grid, ensuring a reliable power supply for remote communities.

Sauli Niinistö, President of the Republic of Finland and Patron of the prize, conferred the Millennium Technology Prize upon Green at a ceremony in Helsinki.

Professor Green said: ‘It is a great honour to have been selected to receive such a prestigious prize. It not only recognises my contribution to photovoltaics [the conversion of light into electrical power], but also the achievements of my students and research colleagues, as well as those of the broader photovoltaic research and commercial community.’

‘I believe the Prize will increase my credibility as a spokesperson for what needs to be done to address climate change. We need to switch from fossil fuels to renewable energy to sustain the trajectory of human civilization on our shared planet. The pace of change is accelerating and the world will shift to solar and wind energy over the coming decade. I believe a huge transformation of historic significance is underway.’

Professor Green and his team are currently working on combined cell technologies to reach 40% solar cell efficiency by exploring options such as stacking cells on top of each other. 

Green said:‘The rapid cost reductions in solar energy that my work has facilitated have come just in time, right at the point when the importance of acting immediately to address climate change has become overwhelmingly obvious.’

Aalto University Professor Päivi Törmä, Chair of the International Selection Committee of the Millennium Technology Prize, said: ‘PERCs can help us provide low-cost energy solutions and mitigate climate change. Continued research on solar cells is needed to replace their constituents that have limited supply, such as silver, with more abundant alternatives.’ 

PERC solar cells are an active research topic also at Aalto University in Professor Hele Savin's group. According to Prof. Savin: ‘PERC technology has enabled us to challenge the famous Shockley-Queisser limit. A good example of this is our recently achieved more than 100 percent quantum efficiency at short wavelengths.’

The Millennium Technology Prize is a Finnish prize awarded in recognition of innovators of technologies that promote sustainable development and a better quality of life. The Prize is one of the world’s largest and most prestigious science and technology prizes and it is presented every other year by the independent Technology Academy Finland (TAF). The winning innovation is selected by the Board of the academy at the recommendation of the International Selection Committee.

Aalto University is one of the strategic partners of Technology Academy Finland, which can propose new members for the International Selection Committee.

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