New Nanoscale Method Could Improve Solar Cell Efficiency

Researchers at the Hong Kong University of Science and Technology have developed a new technique to enhance the efficiency and stability of perovskite solar cells. The study focuses on controlling the distribution of cations—positively charged ions—within the perovskite material at the nanoscale.

Cations are essential in solar cells as they influence the material’s ability to convert sunlight into electricity. However, uneven distribution of these charged particles often leads to defects, reducing the performance and durability of the cells. The research team, led by Dr Yuanyuan Zhou, devised a method to homogenise the arrangement of cations, ensuring a more uniform structure.

Using advanced cathodoluminescence imaging, the team discovered that nanoscale groove traps at the perovskite grain's triple junctions were impeding cation distribution. Using butylammonium acetate as a chemical additive, they reduced the depth of these groove traps by a factor of three. This led to more homogeneous cation distribution, resulting in improved solar cell efficiency of nearly 26% and enhanced stability under test conditions.

As we have previously reported, perovskite materials are seen as a promising alternative to traditional silicon-based solar panels due to their lower production costs and high energy efficiency. However, issues with stability have hindered their commercialisation.

This new method addresses these challenges, potentially leading to more reliable and cost-effective solar panels. The research, conducted in collaboration with institutions including Yale University, Oak Ridge National Laboratory, Yonsei University, and Hong Kong Baptist University, contributes to advancing renewable energy technologies, supporting global efforts to transition to sustainable energy sources.