Griffith University scientists have developed a molecular waterproofing technique to improve the humidity tolerance of new solar cell technology.
The cells, based on a compound known as perovskite, are cheaper to make than traditional silicon cells, but their use in real-world devices has long been limited by a reduced efficiency in humid conditions, such as exist in Queensland.
However, researchers have now developed a water-resistant perovskite solar cell that can operate in a humid environment and maintain efficiency for longer.
Professor Huijun Zhao and Dr Yun Wang, from the Centre for Clean Environment and Energy within Griffith’s Environmental Futures Research Institute, led the Australian-Chinese project.
The breakthrough is an important step towards large-scale production of high-performance perovskite-based devices, deemed by many to represent the next wave of solar energy technology.
“The ‘holy grail’ of solar technologies is in their cost, efficiency, and stability,” said Professor Zhao, Director of the Centre for Clean Environment and Energy. “Cost and efficiency are the advantages of perovskite solar cells, but it is the stability issue that will directly determine their fate.
“We invented a simple dipping technique capable of functionalising perovskite films with some common moisture-tolerant molecules.
“The molecules adsorbed on the perovskite surface have a unique feature of high water resistance, resulting in the perovskite structures remaining stable after 30 days of long-term testing under 90 per cent relative humidity.”
Granted access to the Raijin supercomputer at the National Computational Infrastructure (NCI) facility in Canberra, Dr Wang conducted electronic structure calculations to achieve an efficient water-resistant layer on the solar cells.
In an interview with NCI, Dr Wang said: “Scientists are currently looking for green technologies by preventing waste, using renewable resources, designing environmentally friendly products, increasing catalytic selectivity and reducing energy consumption.”
“Using state-of-the-art quantum mechanics techniques combined with the development of data and materials science, scientists can now do ‘virtual’ screening of candidate materials to theoretically forecast their performance through comprehensive understanding of their structural, electronic, magnetic and optical properties.”
Dr Wang added the research is in response to long-term environmental and energy-related crises driven by population growth, limited fossil resources, pollution, and climate change.
“The screening of potential functional materials is an important step for using cheap, earth-abundant materials to improve renewable energy resources,” he said.
Professor Zhao said the development brought scientists one step closer to the ‘holy grail’ of efficient, stable and cost-effective photovoltaic technology.
“These functionalised perovskites can exhibit similar photovoltaic performance to the pristine ones,” he said.“As well, this functionalisation technique is also the simplest, involving only dipping and washing steps. As such, it can be readily scaled up and adopted by manufacturers.”
Funding for the research came from the Australian Government, Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China.
The research is published in the prestigious journal Nature Energy.