Stabilization of highly efficient perovskite solar cells with a tailored supramolecular interface

Article https://doi.org/10.1038/s41467-024-51550-z Stabilization of highly efficient perovskite solar cells with a tailored supramolecular interface Received: 4 March 2024 Check for updates 1234567890():,; 1234567890():,; Accepted: 12 August 2024 Chenxu Zhao 1,2,3,10, Zhiwen Zhou1,4,10 , Masaud Almalki1,5,10, Michael A. Hope 6, Jiashang Zhao7, Thibaut Gallet8, Anurag Krishna 1, Aditya Mishra6, Felix T. Eickemeyer 1, Jia Xu2, Yingguo Yang 9, Shaik M. Zakeeruddin 1, Alex Redinger 8, Tom J. Savenije 7, Lyndon Emsley 6, Jianxi Yao2 , Hong Zhang 3 & Michael Grätzel 1 The presence of defects at the interface between the perovskite film and the carrier transport layer poses significant challenges to the performance and stability of perovskite solar cells (PSCs). Addressing this issue, we introduce a dual host-guest (DHG) complexation strategy to modulate both the bulk and interfacial properties of FAPbI3-rich PSCs. Through NMR spectroscopy, a synergistic effect of the dual treatment is observed. Additionally, electrooptical characterizations demonstrate that the DHG strategy not only passivates defects but also enhances carrier extraction and transport. Remarkably, employing the DHG strategy yields PSCs with power conversion efficiencies (PCE) of 25.89% (certified at 25.53%). Furthermore, these DHG-modified PSCs exhibit enhanced operational stability, retaining over 96.6% of their initial PCE of 25.55% after 1050 hours of continuous operation under one-sun illumination, which was the highest initial value in the recently reported articles. This work establishes a promising pathway for stabilizing high-efficiency perovskite photovoltaics through supramolecular engineering, marking a significant advancement in the field. Metal halide perovskites are poised to revolutionize next-generation photovoltaics (PVs), owing to their exceptional optoelectronic properties and compatibility with low-cost, large-scale fabrication methods1–8. Similar to organic solar cells9–11 and dye-sensitized solar cells12, perovskite solar cells (PSCs) have a shorter energy payback time (more than 4 times) and lower equivalent greenhouse gas emissions than state-of-art crystalline silicon (c-Si) solar cells (less than 2 times) over their lifecycle13. The leap forward in a short period of time in the power conversion efficiency (PCE) in PSCs is unprecedented, with PCEs emerging from 3.8%3 in its first study to a current certified value of 1 Laboratory of Photonics and Interfaces, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. 2State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization, North China Electric Power University, Beijing, P. R. China. 3State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, China. 4Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China. 5Future Energy Technology Institute, King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086 Riyadh, Saudi Arabia. 6Laboratory of Magnetic Resonance, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. 7Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands. 8Scanning Probe Microscopy Laboratory, Department of Physics and Materials Science, University of, Luxembourg, Luxembourg. 9School of Microelectronics, Fudan University, e-mail: ; Shanghai, P. R. China. 10These authors contributed equally: Chenxu Zhao, Zhiwen Zhou, Masaud Almalki. ; ; michael.graetzel@epfl.ch Nature Communications | (2024)15:7139 1 Article 26.7% in single-junction PSCs, approaching the performance level of c-Si solar cells14. Given their low manufacturing costs and impressive device performance, PSCs have the potential to significantly reduce the levelized cost of electricity, thereby economically driving the global energy transition15. However, despite their promise, the commercialization of PSCs is impeded by their operational stability issue, caused mostly by the unstable perovskite interface with the carrier transport layers16,17. Although tremendous efforts have been applied to solve these problems, it is still challenging to match the lifetime of silicon cells when operating state-of-the-art PSCs (PCE > 25%) under sunlight illumination at elevated temperatures. Currently, there is an ongoing global effort to mitigate the instability of the emerging PSCs, and many of these endeavors are focused on developing new compositions, processing methods, and passivation strategies18–26. In particular, tailoring supramolecular agents with different structures and properties to reduce the concentration of defects in perovskite materials has been demonstrated to be an effective approach for enhancing the photovoltaic performance of PSCs (Supplementary Table 1)19,22,23,27–53. Previous studies have revealed that nanoscale impurities (e.g., PbI2) and defects located at the bulk and surface of perovskite films play a crucial role in driving the rapid degradation of PSCs under sunlight illumination54–56. We recently showed that infusion of cesium iodide (CsI) into perovskite films through a supramolecular approach based on host–guest complexation effectively stabilized the photoactive perovskite phase by suppressing PbI2 impurities and non-photoactive perovskite phases27. Although the photovoltaic performance and operational stability significantly improved, the insulating crown ether host molecule used creates a charge transport (hole transfer) barrier between the perovskite and the hole transport layer (HTL)57. Herein, we report a dual host–guest (DHG) complexation strategy to modulate the electrical and optoelectronic properties of FAPbI3-rich perovskites. Specifically, we sequentially treat the perovskite surface with a Cs–crown-ether complex and an organic ammonium salt. NMR spectroscopy demonstrates that the ammonium environment is modified by the crown ether. Electro-optical characterizations show that the DHG strategy not only passivates surface and bulk defects but also improves the carrier transport between the perovskite and the HTL. The DHG-treated perovskite films exhibit less non-radiative charge carrier recombination losses, indicating a lower defect density, and a significantly improved charge extraction from the perovskite film to the HTL. We observed an improvement of ~ 60 mV for the opencircuit voltage (VOC) of the DHG-treated perovskite devices as compared to the control devices. As a result, the best-performing device yielded a high PCE of 25.89% (25.53% certified), accompanied by an enhancement in operational stability. The DHG-treated PSCs retain over 96.6% of their initial PCE of 25.55% after 1050 h continuous operation under one-sun illumination. This wo (...truncated)