Harnessing the sun
A team of researchers from the Hong Kong University of Science and Technology and Hong Kong Baptist University has made a significant discovery that promises to enhance the efficiency and stability of perovskite solar cells. Led by Dr Yuanyuan Zhou, the team identified surface concavities on individual crystal grains of perovskite thin films, which negatively impact the film's properties and reliability.
Perovskites are materials that share a specific crystal structure originally found in the mineral calcium titanium oxide. They can be synthesised in laboratories and manufactured for various applications. And as we reported recently, perovskite solar cells have shown great potential to surpass traditional silicon solar cells in various applications due to their higher power conversion efficiencies, lower material costs, and versatility. However, their commercialisation has been hindered by stability issues under light, humidity, and thermal conditions.
The researchers tackled this problem by using tridecafluorohexane-1-sulfonic acid potassium to eliminate the grain surface concavities. This innovative approach led to significant improvements in the solar cells' performance during standardised thermal cycling, damp heat, and maximum power-point tracking tests.
The study, conducted in collaboration with Yale University and published in the journal Nature Energy, highlights the importance of understanding the microstructure of perovskite materials. According to the researchers, the surface concavities are often overlooked but are crucial in determining the efficiency and stability of the cells.
This discovery could lead to more reliable and efficient perovskite solar cells, a step towards increasing the generation of sustainable energy.