Understanding the impact of surface roughness: changing from FTO to ITO to PEN/ITO for flexible perovskite solar cells

Philippe Holzhey; Michael Prettl; Silvia Collavini; Claudiu Mortan; Michael Saliba

doi:10.1038/s41598-023-33147-6

Understanding the impact of surface roughness: changing from FTO to ITO to PEN/ITO for flexible perovskite solar cells

Sci Rep. 2023 Apr 19;13(1):6375. doi: 10.1038/s41598-023-33147-6.

Authors

Philippe Holzhey^#¹, Michael Prettl^#², Silvia Collavini³, Claudiu Mortan², Michael Saliba^{4

5}

Affiliations

¹ Adolphe Merkle Institute, University of Fribourg, 1700, Fribourg, Switzerland.
² Institute for Photovoltaics, University of Stuttgart, Stuttgart, Germany.
³ , San Sebastián, Spain.
⁴ Institute for Photovoltaics, University of Stuttgart, Stuttgart, Germany. michael.saliba@ipv.uni-stuttgart.de.
⁵ IEK-5 Photovoltaik, Forschungszentrum Jülich GmbH, Jülich, Germany. michael.saliba@ipv.uni-stuttgart.de.

^# Contributed equally.

Abstract

So far, single-junction flexible PSCs have been lacking in efficiency compared to rigid PSCs. Recently, > 23% have been reported. We therefore focus on understanding the differences between rigid and flexible substrates. One often neglected parameter is the different surface roughness which directly affects the perovskite film formation. Therefore, we adjust the layer thickness of SnO₂ and the perovskite layers. Furthermore, we introduce a PMMA layer between the perovskite and the hole transporting material (HTM), spiro-MeOTAD, to mitigate shunting pathways. In addition, the multication perovskite Rb_0.02Cs_0.05FA_0.77MA_0.16Pb(I_0.83Br_0.17)₃ is employed, resulting in stabilized performances of 16% for a flexible ITO substrate and 19% on a rigid ITO substrate.