Surface Property Tuning of Methylammonium Lead Iodide by Plasma for Use in Planar Perovskite Solar Cells

Masoud Shekargoftar; Jan Pospisil; Ján Dugáček; Martin Weiter; Tomáš Homola

doi:10.1021/acsomega.0c02179

Surface Property Tuning of Methylammonium Lead Iodide by Plasma for Use in Planar Perovskite Solar Cells

ACS Omega. 2020 Jul 16;5(29):18384-18390. doi: 10.1021/acsomega.0c02179. eCollection 2020 Jul 28.

Authors

Masoud Shekargoftar¹, Jan Pospisil², Ján Dugáček¹, Martin Weiter², Tomáš Homola¹

Affiliations

¹ R&D Center for Low-Cost Plasma and Nanotechnology Surface Modifications (CEPLANT), Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic.
² Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic.

Abstract

The demand for cheap and green energy as a replacement for fossil fuels has never been greater, and perovskite solar cells (PSCs) are among the leading means of meeting it. The surface properties of metal halide perovskite layers play crucial roles in the performance and durability of such cells. Consequently, a wide range of engineering processes for surface modification of perovskite layers has been investigated and among them is atmospheric pressure plasma (APP). Nevertheless, knowledge of the interaction between plasma and perovskite layers is still far from complete. In this work, CH₃NH₃PbI₃ films were subjected to APP generated by a portable plasma source. A detailed understanding of band energy after plasma treatment is crucial to the investigation of the behavior of the perovskite layer. This study demonstrates a remarkable shift in the valence and conduction bands of a perovskite layer after plasma treatment, while band gap energy remains relatively constant. We found that short plasma treatment of perovskite layers resulted in higher performance and stability of PSCs.