One-Step Thermal Gradient- and Antisolvent-Free Crystallization of All-Inorganic Perovskites for Highly Efficient and Thermally Stable Solar Cells

Mahdi Malekshahi Byranvand; Tim Kodalle; Weiwei Zuo; Theresa Magorian Friedlmeier; Maged Abdelsamie; Kootak Hong; Waqas Zia; Shama Perween; Oliver Clemens; Carolin M Sutter-Fella; Michael Saliba

doi:10.1002/advs.202202441

One-Step Thermal Gradient- and Antisolvent-Free Crystallization of All-Inorganic Perovskites for Highly Efficient and Thermally Stable Solar Cells

Adv Sci (Weinh). 2022 Aug;9(23):e2202441. doi: 10.1002/advs.202202441. Epub 2022 Jun 19.

Authors

Mahdi Malekshahi Byranvand^{1

2}, Tim Kodalle³, Weiwei Zuo¹, Theresa Magorian Friedlmeier⁴, Maged Abdelsamie⁵, Kootak Hong⁶, Waqas Zia^{1

2}, Shama Perween⁷, Oliver Clemens⁷, Carolin M Sutter-Fella³, Michael Saliba^{1

2}

Affiliations

¹ Institute for Photovoltaics (ipv), University of Stuttgart, Pfaffenwaldring 47, 70569, Stuttgart, Germany.
² Helmholtz Young Investigator Group FRONTRUNNER, IEK5-Photovoltaik, Forschungszentrum Jülich, 52425, Jülich, Germany.
³ Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
⁴ Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), 70563, Stuttgart, Germany.
⁵ Materials Sciences Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
⁶ Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
⁷ Institute for Materials Science, Chemical Materials Synthesis, University of Stuttgart, 70569, Stuttgart, Germany.

Abstract

All-inorganic perovskites have emerged as promising photovoltaic materials due to their superior thermal stability compared to their heat-sensitive hybrid organic-inorganic counterparts. In particular, CsPbI₂ Br shows the highest potential for developing thermally-stable perovskite solar cells (PSCs) among all-inorganic compositions. However, controlling the crystallinity and morphology of all-inorganic compositions is a significant challenge. Here, a simple, thermal gradient- and antisolvent-free method is reported to control the crystallization of CsPbI₂ Br films. Optical in situ characterization is used to investigate the dynamic film formation during spin-coating and annealing to understand and optimize the evolving film properties. This leads to high-quality perovskite films with micrometer-scale grain sizes with a noteworthy performance of 17% (≈16% stabilized), fill factor (FF) of 80.5%, and open-circuit voltage (V_OC ) of 1.27 V. Moreover, excellent phase and thermal stability are demonstrated even after extreme thermal stressing at 300 °C.

Keywords: CsPbI2Br; all-inorganic perovskites; crystallization; in situ characterization.

Abstract

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