A new molecular waterproofing technique developed by scientists from Griffith University could open the way to a new, high-efficiency solar cell technology.
Solar cells made from perovskite compounds are cheaper to make than traditional silicon cells, and are also said to be more efficient. However, they were limited by their instability in humid conditions, which reduced their efficiency.
Professor Huijun Zhao and Dr Yun Wang, from the Centre for Clean Environment and Energy within Griffith’s Environmental Futures Research Institute, led the project.
Professor Zhao, Director of the Centre for Clean Environment and Energy, said the invention centres around a simple dipping technique capable of functionalising perovskite films with 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,” he explained.
The functionalisation of the perovskites did not greatly affect the photovoltaic performance of the solar cells, exhibiting similar efficiency compared to the pristine ones. Additionally, because the functionalisation technique is simple, involving only dipping and washing steps, this process can be readily scaled up and adopted by manufacturers.
The development is a step closer to the holy grail of photovoltaic technology: a solar cell which is efficient, stable and cost-effective to manufacture.
Key to the breakthrough was the scientists' access to the Raijin supercomputer at the National Computational Infrastructure (NCI) facility in Canberra. This computing power allowed Dr Wang to use state-of-the-art quantum mechanics techniques combined with materials science to virtually screen candidate materials, in order to forecast their performance, and gain a comprehensive understanding of their structural, electronic, magnetic and optical properties.
These electronic structure calculations allowed the researchers to achieve an efficient water-resistant layer on the solar cells.
Other engineering outcomes that can result from this increased computing capability include research into green technologies by preventing waste, using renewable resources, designing environmentally friendly products, increasing catalytic selectivity and reducing energy consumption.
These goals and areas of research can help formulate solutions 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,” said Dr Wang.