Prof. YANG Guang, Assistant Professor in the Department of Electrical and Electronic Engineering (EEE), together with a team from Zhejiang University, has identified a previously overlooked cause of ageing in perovskite solar cells exposed to light. The study was published in Watt. Prof. Nam-Gyu PARK of Sungkyunkwan University, Korea, commended the work in a research highlight in the same journal.
Perovskite solar cells are efficient, low-cost and lightweight, making them a promising next-generation solar technology. However, their performance gradually declines under prolonged exposure to sunlight, a major barrier to large-scale commercialisation. The team found that uneven charge losses at boundaries between neighbouring grains with different crystal facets can accelerate degradation. Defects on one side of these boundaries cause a build-up of positively charged holes, making otherwise more light-resistant grains degrade faster.
To address this issue, the researchers added 3-fluorophenylethylammonium bromide (m-F-PEABr). The compound collects at grain boundaries and fills vacancies, balancing charge losses on both sides. Treated cells achieved 26.55% power conversion efficiency and retained over 90% of their initial efficiency after more than 2,200 hours of continuous operation under light equivalent to one sun.
The findings provide a new approach to improving cell efficiency and stability, addressing a major barrier to the commercialisation of perovskite solar cells.
More details is posted here: https://www.polyu.edu.hk/media/media-releases/2026/1104_polyu-research-uncovers-hidden-cause-of-ageing-in-perovskite-solar-cells/
