Intermediate-Phase Engineering via Dimethylammonium Cation Additive for Stable Perovskite Solar Cells
Philippe Holzhey a b, David McMeekin a b, Sebastian Fürer b, Steven Harvey c, Laura Schelhas c, James Ball a, Suhas Mahesh a, Seongrok Seo a, Nicholas Hawkins d, Jianfeng Lu b, Michael Johnston a, Joseph Berry c, Udo Bach b, Henry Snaith a
a Department of Physics, University of Oxford, UK
b ARC Centre of Excellence in Exciton Science, Department of Chemical and Biological Engineering, Monash University, Clayton, VIC, Australia
c Material Science Center, National Renewable Energy Laboratory, Golden, CO 80401, USA, Denver West Parkway, 15013, Golden, United States
d Department of Zoology, University of Oxford, 11a Mansfield Rd, Oxford, United Kingdom
Oral, Philippe Holzhey, presentation 098
Publication date: 6th February 2024

Achieving the long-term stability of perovskite solar cells is arguably the most critical challenge to enabling their widespread commercialisation. Understanding the perovskite crystallisation process and its direct impact on device stability is essential to achieve this goal. Surprisingly, we find that the intermediate phases that occur during the crystallization process strongly influence the long-term perovskite device stability. The commonly employed dimethyl formamide/dimethyl sulfoxide (DMF/DMSO) solvent system preparation method results in poor crystal quality and microstructure of the polycrystalline perovskite films. In this work, we introduce a high-temperature DMSO-free processing method that utilizes dimethylammonium chloride (DMACl) as an additive to control the perovskite intermediate precursor phases. By precisely controlling the 2H to 3C perovskite phase crystallization sequence, we tune the grain size, texturing, orientation (corner-up vs face-up), and crystallinity of the formamidinium (FA)yCs1-yPb(IxBr1-x)3 perovskite system. Encapsulated devices show significantly improved operational stability, with a champion device showing a T80 of 490 hours under simulated sunlight at 85 °C in air, under open circuit conditions. Our work introduces a new processing method that allows higher overall perovskite device stability by controlling the intermediate phase domains during the perovskite formation. This work highlights the importance of material quality to achieve long-term operational stability of perovskite optoelectronic devices. [1]

The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 763977 of the PerTPV project and the innovation programme under Marie Skłodowska-Curie grant agreement no. 764787. We also acknowledge the financial support from the Australian Research Council Centre of Excellence in Exciton Science (ACEx:CE170100026). D.P.M. acknowledges the Marie Skłodowska-Curie grant agreement SAMA no. 101029896. The work by S.P.H. and L.T.S was supported by the De-Risking Halide Perovskite Solar Cells programme of the National Center for Photovoltaics, funded by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Solar Energy Technologies Office under US Department of Energy contract no. DE-AC36-08GO28308 with Alliance for Sustainable Energy, LLC, the Manager and Operator of the National Renewable Energy Laboratory. Work by J.J.B. was supported by the Office of Naval Research. The views expressed in the article do not necessarily represent the views of the US Department of Energy or the US Government. We acknowledge F. Vollrath and the Oxford Silk Group for their help and equipment. We also acknowledge the Monash X-ray Platform.

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info