Paper alert - single grain level to devices in perovskite PV!

© 2024 EES

© 2024 EES

PV-Lab is happy to share that our latest paper "Alleviating nanostructural phase impurities enhances the optoelectronic properties, device performance and stability of cesium-formamidinium metal–halide perovskites" has been published in Energy & Environmental Science !

PV-Lab is happy to share that our latest paper "Alleviating nanostructural phase impurities enhances the optoelectronic properties, device performance and stability of cesium-formamidinium metal–halide perovskites" has been published in Energy & Environmental Science!

A big thanks to all the co-authors Mostafa Othman*, Quentin Jeangros, Daniel A. Jacobs, Moritz H. Futscher, Stefan Zeiske, Ardalan Armin, Anael Jaffres, Austin G. Kuba, Dmitry Chernyshov, Sandra Jenatsch, Simon Zu¨fle, Beat Ruhstaller, Saba Tabean, Tom Wirtz, Santhana Eswara, Jiashang Zhao, Tom J. Savenije, Christophe Ballif, Christian M. Wolff* and Aïcha Hessler-Wyser* for the fruitful collaboration!

Highlights from the article;

''The technique of alloying FA+ with Cs+ is often used to promote structural stabilization of the desirable α-FAPbI3 phase in halide perovskite devices. However, the precise mechanisms by which these alloying approaches improve the optoelectronic quality and enhance the stability have remained elusive. In this study, we advance that understanding by investigating the effect of cationic alloying in CsxFA1−xPbI3 perovskite thin-films and solar-cell devices. Selected-area electron diffraction patterns combined with microwave conductivity measurements reveal that fine Cs+ tuning (Cs0.15FA0.85PbI3) leads to a minimization of stacking faults and an increase in the photoconductivity of the perovskite films. Ultra-sensitive external quantum efficiency, kelvin-probe force microscopy and photoluminescence quantum yield measurements demonstrate similar Urbach energy values, comparable surface potential fluctuations and marginal impact on radiative emission yields, respectively, irrespective of Cs content. Despite this, these nanoscopic defects appear to have a detrimental impact on inter-grains’/domains’ carrier transport, as evidenced by conductive-atomic force microscopy and corroborated by drastically reduced solar cell performance. Importantly, encapsulated Cs0.15FA0.85PbI3 devices show robust operational stability retaining 85% of the initial steady-state power conversion efficiency for 1400 hours under continuous 1 sun illumination at 35 °C, in open-circuit conditions. Our findings provide nuance to the famous defect tolerance of halide perovskites while providing solid evidence about the detrimental impact of these subtle structural imperfections on the long-term operational stability.''

Funding

This project has received funding from the European Union's Horizon 2020 research and innovation programme (Marie Skłodowska-Curie grant agreement no. 945363, VIPERLAB, 101006715; TRIUMPH, 101075725), the Swiss National Science Foundation (PAPET, 200021_197006; A3P, 40B2-0_1203626), the Swiss Federal Office of Energy (PRESTO), and the ETH Domain through an AM grant (AMYS). M. H. F. is supported by a Rubicon Fellowship from the Netherlands Organisation for Scientific Research (NWO). A. A. acknowledges support from the Welsh Government's Sêr Cymru II Rising Star through the European Regional Development Fund, Welsh European Funding Office, and Swansea University Strategic Initiative in Sustainable Advanced Materials. The authors thank Dr Rita Therisod and Dr Victor Boureau of the Cimé for the support of the TEM experiments. The SIMS part of the work was funded by the Luxembourg National Research Fund (FNR) by the grant PRIDE17/12246511/PACE.