Evaluation of surface passivating solvents for single and mixed halide perovskites

Mehmet Derya Özeren; Áron Pekker; Katalin Kamarás; Bea Botka

doi:10.1039/d2ra04278a

Evaluation of surface passivating solvents for single and mixed halide perovskites

RSC Adv. 2022 Oct 11;12(44):28853-28861. doi: 10.1039/d2ra04278a. eCollection 2022 Oct 4.

Authors

Mehmet Derya Özeren^{1

2}, Áron Pekker¹, Katalin Kamarás¹, Bea Botka¹

Affiliations

¹ Institute for Solid State Physics and Optics, Wigner Research Centre for Physics Konkoly Thege u. 29-33 H-1121 Budapest Hungary kamaras.katalin@wigner.hu bea.botka@wigner.hu.
² Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics Műegyetem rkp. 3 H-1111 Budapest Hungary.

Abstract

Surface passivation is one of the commonly used approaches to reduce the density of defects on the surfaces and interfaces hindering the performance and stability of perovskite optoelectronic devices. Although surface passivation leads to performance improvement for the targeted devices, details of the complex intermolecular interactions occurring between the molecules and perovskites are not entirely known. Here, we investigated a variety of commonly used solvents in the post-processing of perovskites by using photoluminescence (PL) spectroscopy on single and mixed halide perovskites (MAPbI₃, MAPbBr₃ and MAPb(Br_0.5I_0.5)₃). Our results show that solvents with medium and low Gutmann donor and acceptor numbers provide PL intensity increase for both single halide perovskites by passivating the surface defect sites. Among the single halide perovskites, MAPbBr₃ is more attracted to hydrogen bonding solvents, in contrast to MAPbI₃ that is preferred by Lewis bases. This halide selective attraction also has an influence on the mixed-halide composition. Identifying these interaction mechanisms provides new insights into passivating the surface of perovskites for future device design.