3D Perovskite Passivation with a Benzotriazole-Based 2D Interlayer for High-Efficiency Solar Cells

Alessandro Caiazzo; Arthur Maufort; Bas T van Gorkom; Willemijn H M Remmerswaal; Jordi Ferrer Orri; Junyu Li; Junke Wang; Wouter T M van Gompel; Kristof Van Hecke; Gunnar Kusch; R A Oliver; Caterina Ducati; Laurence Lutsen; Martijn M Wienk; Samuel D Stranks; Dirk Vanderzande; René A J Janssen

doi:10.1021/acsaem.3c00101

3D Perovskite Passivation with a Benzotriazole-Based 2D Interlayer for High-Efficiency Solar Cells

ACS Appl Energy Mater. 2023 Mar 27;6(7):3933-3943. doi: 10.1021/acsaem.3c00101. eCollection 2023 Apr 10.

Authors

Alessandro Caiazzo¹, Arthur Maufort², Bas T van Gorkom¹, Willemijn H M Remmerswaal¹, Jordi Ferrer Orri^{3

4

5}, Junyu Li¹, Junke Wang¹, Wouter T M van Gompel², Kristof Van Hecke⁶, Gunnar Kusch⁴, R A Oliver⁴, Caterina Ducati⁴, Laurence Lutsen², Martijn M Wienk¹, Samuel D Stranks^{3

5}, Dirk Vanderzande², René A J Janssen^{1

7}

Affiliations

¹ Molecular Materials and Nanosystems and Institute of Complex Molecular Systems Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
² Institute for Materials Research (IMO-IMOMEC), Hybrid Materials Design, Hasselt University, Martelarenlaan 42, B-3500 Hasselt, Belgium.
³ Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
⁴ Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS, United Kingdom.
⁵ Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
⁶ XStruct, Department of Chemistry, Ghent University, Krijgslaan 281-S3, B-9000 Ghent, Belgium.
⁷ Dutch Institute for Fundamental Energy Research, De Zaale 20, 5612 AJ Eindhoven, The Netherlands.

Abstract

2H-Benzotriazol-2-ylethylammonium bromide and iodide and its difluorinated derivatives are synthesized and employed as interlayers for passivation of formamidinium lead triiodide (FAPbI₃) solar cells. In combination with PbI₂ and PbBr₂, these benzotriazole derivatives form two-dimensional (2D) Ruddlesden-Popper perovskites (RPPs) as evidenced by their crystal structures and thin film characteristics. When used to passivate n-i-p FAPbI₃ solar cells, the power conversion efficiency improves from 20% to close to 22% by enhancing the open-circuit voltage. Quasi-Fermi level splitting experiments and scanning electron microscopy cathodoluminescence hyperspectral imaging reveal that passivation provides a reduced nonradiative recombination at the interface between the perovskite and hole transport layer. Photoluminescence spectroscopy, angle-resolved grazing-incidence wide-angle X-ray scattering, and depth profiling X-ray photoelectron spectroscopy studies of the 2D/three-dimensional (3D) interface between the benzotriazole RPP and FAPbI₃ show that a nonuniform layer of 2D perovskites is enough to passivate defects, enhance charge extraction, and decrease nonradiative recombination.