Prestigious Engineering Prize Awarded to Pioneering Solar Team

A prestigious engineering prize has been awarded to a team of scientists who helped enable the green energy transition by boosting the efficiency of solar cells.

Professor Martin Green, Professor Andrew Blakers and entrepreneurs Dr. Aihua Wang and Dr. Jianhua Zhao won the 2023 Queen Elizabeth Prize (QEPrize) for Engineering for inventing and perfecting the Passivated Emitter and Rear Cell (PERC) solar photovoltaic technology that now makes up 90 percent of the worldwide solar cell market. 

“The QEPrize celebrates the engineers who time and time again solve the impossible and transform our world for the better. PERC solar technology is one of those innovations,” QEPrize Foundation chair Lord Browne of Madingley said in a press release. “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. This year’s innovation has been and will continue to be integral to this journey.”

The road to photovoltaic solar cells was paved by Albert Einstein, whose 1905 work on the photoelectric effect explained the photovoltaic effect for the first time. The first photovoltaic cells were designed by Bell Telephone Laboratories in 1954. However, early solar cells were mostly used on satellites in space and were cripplingly expensive here on Earth until the 1970s, BBC News explained. 

This was when, in the wake of the oil crisis, Green decided to focus on improving their performance. At the time, researchers believed that the most efficiency a single-layer silicon solar cell could boast was 20 percent, according to the QEPrize website. However, the award recipients and others believed it was possible to reach a theoretical efficiency of 30 percent with Green suggesting a practical limit of 25 percent. 

In the 1980s, Green and Blakers at the University of New South Wales managed to achieve efficiency of first 18 percent, then 19 percent, then 20 percent. In 1989, Green, Blakers, Wang, Zhao and others published their first paper on PERC technology where they announced a record efficiency of 22.8 percent. Wang and Zhao later managed to lead work that achieved Green’s 25 percent efficiency target. 

How were they able to do this? By changing the way that the cell’s rear was designed.

“Traditionally, the rear surface just had a layer of metal aluminium printed directly into it, and so that wasn’t a very good reflector of light. And it also gobbled up any electron that went anywhere near the back surface,” Blakers explained to BBC News. “Replacing that crude back metal contact with a more sophisticated contact served both purposes and led to quite significant increases in cell efficiency.”

Because the commercial need for solar cells was not strong when the scientists first conducted their research, they chose to publish their designs instead of patenting them, according to the QEPrize website. This meant that the technology could be taken up around the world once societies began to wake up to the realities of the climate crisis and the need to develop non-fossil forms of energy. Zhao and Wang helped China to become the global leader in PERC production when they brought their work with Green home after their studies.

“We were among the first to start Perc production,” Zhao told BBC News.

Today, one out of every seven solar panels is made in one Chinese factory. Globally, solar now makes up about a half of all newly constructed electricity generation capacity, and solar capacity is set to triple by 2027, according to the International Energy Agency. Solar is now the cheapest electricity source in the majority of countries, according to the QEPrize website.

“We are in the process of global energy transition, with PERC and solar power in the front seat, and I wholeheartedly congratulate Professors Green and Blakers, and Drs Wang and Zhao for their contribution to humanity,” Lord Browne said in the press release. 

The four scientists will receive £500,000 and a special trophy. They will also be honored at a ceremony later this year. 

Green also won the Millennium Technology Prize in 2022, according to The Sydney Morning Herald, and there is speculation he may be nominated for a Nobel Prize in the future.