Surface chemical polishing and passivation minimize non-radiative recombination for all-perovskite tandem solar cells

• Published in: Nature communications 2024-08, Vol.15 (1), p.7335-10
• Main Authors: Pan, Yongyan, Wang, Jianan, Sun, Zhenxing, Zhang, Jiaqi, Zhou, Zheng, Shi, Chenyang, Liu, Sanwan, Ren, Fumeng, Chen, Rui, Cai, Yong, Sun, Huande, Liu, Bin, Zhang, Zhongyong, Zhao, Zhengjing, Cai, Zihe, Qin, Xiaojun, Zhao, Zhiguo, Ji, Yitong, Li, Neng, Huang, Wenchao, Liu, Zonghao, Chen, Wei
• Format: Article
• Language: English
• Subjects: 639/301/299/946; 639/4077/909/4101/4096/946; Chemical polishing; Efficiency; Electron transport; Energy conversion efficiency; Energy gap; Energy loss; Humanities and Social Sciences; Lead; multidisciplinary; Perovskites; Photovoltaic cells; Radiative recombination; Reagents; Recombination; Science; Science (multidisciplinary); Solar cells; Stoichiometry; Surface defects; Tin
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-51703-0

All-perovskite tandem solar cells have shown great promise in breaking the Shockley–Queisser limit of single-junction solar cells. However, the efficiency improvement of all-perovskite tandem solar cells is largely hindered by the surface defects induced non-radiative recombination loss in Sn–Pb mixed narrow bandgap perovskite films. Here, we report a surface reconstruction strategy utilizing a surface polishing agent, 1,4-butanediamine, together with a surface passivator, ethylenediammonium diiodide, to eliminate Sn-related defects and passivate organic cation and halide vacancy defects on the surface of Sn–Pb mixed perovskite films. Our strategy not only delivers high-quality Sn–Pb mixed perovskite films with a close-to-ideal stoichiometric ratio surface but also minimizes the non-radiative energy loss at the perovskite/electron transport layer interface. As a result, our Sn–Pb mixed perovskite solar cells with bandgaps of 1.32 and 1.25 eV realize power conversion efficiencies of 22.65% and 23.32%, respectively. Additionally, we further obtain a certified power conversion efficiency of 28.49% of two-junction all-perovskite tandem solar cells. The efficiency of all-perovskite tandem solar cells is impacted by the nonradiative recombination loss in Sn–Pb mixed narrow bandgap perovskite films. Here, the authors utilize a surface polishing agent with surface passivator to deliver films with a close-to-ideal stoichiometric ratio surface.