Effect of Cation Composition on the Mechanical Stability of Perovskite Solar Cells |
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| Authors: | Nicholas Rolston Adam D Printz Jared M Tracy Hasitha C Weerasinghe Doojin Vak Lew Jia Haur Anish Priyadarshi Nripan Mathews Daniel J Slotcavage Michael D McGehee Roghi E Kalan Kenneth Zielinski Ronald L Grimm Hsinhan Tsai Wanyi Nie Aditya D Mohite Somayeh Gholipour Michael Saliba Michael Grätzel Reinhold H Dauskardt |
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| Institution: | 1. Department of Applied Physics, Stanford University, Stanford, CA, USA;2. Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA;3. Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, VIC, Australia;4. Energy Research Institute@NTU, Nanyang Technological University, Singapore;5. School of Materials Science and Engineering, Nanyang Technological University, Singapore;6. Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA, USA;7. Materials Physics and Application Division, Los Alamos National Laboratory, Los Alamos, NM, USA;8. Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, école Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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| Abstract: | Photoactive perovskite semiconductors are highly tunable, with numerous inorganic and organic cations readily incorporated to modify optoelectronic properties. However, despite the importance of device reliability and long service lifetimes, the effects of various cations on the mechanical properties of perovskites are largely overlooked. In this study, the cohesion energy of perovskites containing various cation combinations of methylammonium, formamidinium, cesium, butylammonium, and 5‐aminovaleric acid is reported. A trade‐off is observed between the mechanical integrity and the efficiency of perovskite devices. High efficiency devices exhibit decreased cohesion, which is attributed to reduced grain sizes with the inclusion of additional cations and PbI2 additives. Microindentation hardness testing is performed to estimate the fracture toughness of single‐crystal perovskite, and the results indicated perovskites are inherently fragile, even in the absence of grain boundaries and defects. The devices found to have the highest fracture energies are perovskites infiltrated into a porous TiO2/ZrO2/C triple layer, which provide extrinsic reinforcement and shielding for enhanced mechanical and chemical stability. |
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| Keywords: | cation mechanical stability perovskite solar cells reliability |
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