Two-dimensional perovskitoids enhance stability in perovskite solar cells

• Published in: Nature (London) Vol. 633; no. 8029; pp. 359 - 364
• Main Authors: Liu, Cheng, Yang, Yi, Chen, Hao, Spanopoulos, Ioannis, Bati, Abdulaziz S. R., Gilley, Isaiah W., Chen, Jianhua, Maxwell, Aidan, Vishal, Badri, Reynolds, Robert P., Wiggins, Taylor E., Wang, Zaiwei, Huang, Chuying, Fletcher, Jared, Liu, Yuan, Chen, Lin X., De Wolf, Stefaan, Chen, Bin, Zheng, Ding, Marks, Tobin J., Facchetti, Antonio, Sargent, Edward H., Kanatzidis, Mercouri G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.09.2024; Nature Publishing Group
• Subjects: 639/301/299/946; 639/4077/909/4101/4096/946; Cations; Cell migration; Charge transport; Dimensional stability; Efficiency; Electrons; Energy conversion efficiency; Heterostructures; Humanities and Social Sciences; Ion migration; Ligands; Microscopy; multidisciplinary; Performance degradation; Perovskites; Photovoltaic cells; Phthalimide; Phthalimides; Science; Science (multidisciplinary); Single crystals; Solar cells; Spectrum analysis; State power
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/s41586-024-07764-8

Two-dimensional (2D) and three-dimensional (3D) perovskite heterostructures have played a key role in advancing the performance of perovskite solar cells 1 , 2 . However, the migration of cations between 2D and 3D layers results in the disruption of octahedral networks, leading to degradation in performance over time 3 , 4 . We hypothesized that perovskitoids, with robust organic–inorganic networks enabled by edge- and face-sharing, could impede ion migration. We explored a set of perovskitoids of varying dimensionality and found that cation migration within perovskitoid–perovskite heterostructures was suppressed compared with the 2D–3D perovskite case. Increasing the dimensionality of perovskitoids improves charge transport when they are interfaced with 3D perovskite surfaces—this is the result of enhanced octahedral connectivity and out-of-plane orientation. The 2D perovskitoid (A6BfP) 8 Pb 7 I 22 (A6BfP: N -aminohexyl-benz[f]-phthalimide) provides efficient passivation of perovskite surfaces and enables uniform large-area perovskite films. Devices based on perovskitoid–perovskite heterostructures achieve a certified quasi-steady-state power conversion efficiency of 24.6% for centimetre-area perovskite solar cells. We removed the fragile hole transport layers and showed stable operation of the underlying perovskitoid–perovskite heterostructure at 85 °C for 1,250 h for encapsulated large-area devices in ambient air. We find that 2D–3D perovskitoid passivation applied to perovskite solar cells impedes cation migration and decreases carrier recombination at the interface, providing enhanced operating stability at elevated temperatures and increased power conversion efficiencies.