Renewable Energy World names its Solar 40 Under 40

Three Australians have made it into Renewable Energy World’s inaugural Solar 40 Under 40 list, acknowledging 40 individuals under the age of 40 whose work is influencing solar technology development at a global level.

Associate Professor Bram Hoex (39), Dr Brett Hallam (32) and Dr Alison Ciesla (32), all from UNSW Sydney, were included on the list thanks to their pioneering work at the School of Photovoltaic and Renewable Energy Engineering (SPREE). They were joined by 37 other individuals from all over the word, many of whom hold executive positions at solar technology companies.

Associate Professor Hoex earned his position on the list due to his research into improving cost-effectiveness of silicon-based solar cells. He explained, “I particularly focus on reducing the losses at the front and rear surface of the solar cell, both the contacted as well as the non-contacted regions. This can be done by applying nanoscale thin films on the silicon surfaces.

“Nanoscale thin films can also be used to extract electron holes selectively, and these kinds of contacts are now enabling world-record solar cell efficiencies,” he added. An electron hole is an absence of an electron where one could exist, which can be traded between atoms in the same way electrons can.

Dr Hallam’s work aims to improve the performance of silicon cells by eliminating or minimising defects in the cell materials. He said, “A key defect that I have been working on is a boron-oxygen complex that, ironically, forms under sunlight and can reduce performance by 10%.

“I have been using atomic hydrogen that is naturally introduced in the solar cell during fabrication, to attach to the defects and electrically neutralise them,” Dr Hallam continued. To achieve this, light 100 times as bright as the sun on the Earth’s surface is used to manipulate the charge state of hydrogen and increase its mobility.

Dr Ciesla, the daughter of late UNSW solar technology pioneer Professor Stuart Wenham, works in the same team as Dr Hallam and so has also been involved with the work on hydrogenation. “The other area of my research is laser doping and plating of metal contacts to improve efficiencies of commercial cells while reducing costs, as used in Suntech Power’s PLUTO cells,” she said.

Looking ahead, there will be an opportunity for the trio to put their heads together on a new project that will combine their strengths. According to Dr Hallam, the project will integrate defect engineering processes such as hydrogenation into high-efficiency solar cell structures using ‘heterojunctions’.

“This could enable high-efficiency solar cells to be fabricated using cheap silicon,” he said.

Members of the Solar 40 Under 40 were recognised this week at the Intersolar North America conference, held in San Francisco. Dr Hallam and Associate Professor Hoex both attended the conference and intend to capitalise on the opportunity of being among the solar industry’s global elite by networking with prospective partners.

“I am hoping to engage with US-based photovoltaic and equipment manufacturers and also visit existing project partners in the Bay area,” Dr Hallam said.

Image caption: Dr Brett Hallam, Dr Alison Ciesla and Associate Professor Bram Hoex.