A research team led by Associate Professor Xie Liqiang and Professor Wei Zhanhua from the Institute of Luminescent Materials and Information Displays and College of Materials Science and Engineering, Huaqiao University (HQU), published an article titled “Ultrathin polymer membrane for improved hole extraction and ion blocking in perovskite solar cells” in Nature Communications, an internationally renowned journal.

Highly efficient perovskite solar cells (PSCs) in the n-i-p structure have demonstrated limited operational lifetimes, primarily due to the layer-to-layer ion diffusion in the perovskite/doped hole-transport layer (HTL) heterojunction, leading to conductivity drop in HTL and component loss in perovskite. Herein, the research introduces an ultrathin (-7 nm)p-type polymeric interlayer (D18) with excellent ion-blocking ability between perovskite and HTL to address these issues. The ultrathin D18 interlayer effectively inhibits the layer-to-layer diffusion of lithium, methylammonium, formamidium, and iodide ions. Additionally, D18 improves the energy-level alignment at the perovskite/HTL interface and facilitates efficient hole extraction. The resulting PSCs achieve efficiencies of 26.39 (certified 26.17) and 25.02% with aperture areas of 0.12 and 1.00 square centimeters respectively. Remarkably, the devices retain 95.4% of the initial efficiency after 1100 hours of operation in maximum power point tracking, representing significant stability advancements for high-efficiency n-i-p PSCs.

The research work, under the guidance of Associate Professor Xie Liqiang and Professor Wei Zhanhua, was jointly completed by HQU’s doctoral students Shen Lina and Song Peiquan, along with Kui Jiang from City University of Hong Kong. The study was supported by the National Natural Science Foundation of China, the Natural Science Foundation of Fujian Province, and the Research Fund of HQU.

Link to the paper: https://www.nature.com/articles/s41467-024-55329-0

(Editor: Wei Linying)