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.


The €1 million global award for technology, conferred every two years, recognised Mr Green’s leadership in the development of 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 per cent of the global solar cell market.

Passivated Emitter and Rear Cell (PERC) innovation



Prof. Green developed the PERC with his team 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 allows the electrons to maintain this excited state – or move freely – for longer, resulting in greater and more efficient energy generation. The PERC has helped increase the conversion efficiency of standard solar cells by over 50 per cent in relative terms from 16.5 per cent in the early 1980s to 25 per cent in the early 2000s.

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.

“A huge transformation is underway”

Sauli Niinistö, President of the Republic of Finland and Patron of the prize, conferred the Millennium Technology Prize upon Prof. Green at a ceremony in Helsinki. “It is a great honour to have been selected to receive such a prestigious prize,” remarked Professor Green. “It not only recognises my contribution to photovoltaics, but also the achievements of my students and research colleagues at UNSW, 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,” he continued. “We need to switch from fossil fuels to renewable energy to sustain the trajectory of human civilisation 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.”

Aim to achieve 40% solar cell efficiency

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

“Solar cells are increasingly being used to replace large power stations that use fossil fuels,” observed Professor Green. “In 2021, 20 countries or regions including Australia, Chile, Germany, Greece, Italy, Netherlands, Spain, Vietnam and California (US) generated between 8 per cent and 25 per cent of their total electricity supply from solar energy, with this number growing quickly.

“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,” he added.

Driving environmental sustainability 
 

Professor Minna Palmroth, Chair of the Board of Technology Academy Finland, said: “Professor Green’s innovation has already and will continue to greatly enhance the quality of life for billions of people globally and enhance environmentally sustainable development, from national power grids to private housing.” 


Professor Päivi Törmä, Chair of the International Selection Committee of the Millennium Technology Prize, further noted that: “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.” 


The 2022 ceremony celebrating Green’s innovation was held alongside the Millennium Innovation Forum – also hosted by Technology Academy Finland. The Forum brings together internationally renowned experts to discuss how technology can solve the world’s greatest challenges.