Minimizing the Trade-Off between Photocurrent and Photovoltage in Triple-Cation Mixed-Halide Perovskite Solar Cells

Thomas Baumeler; Neha Arora; Alexander Hinderhofer; Seckin Akin; Alessandro Greco; Mojtaba Abdi-Jalebi; Ravichandran Shivanna; Ryusuke Uchida; Yuhang Liu; Frank Schreiber; Shaik M Zakeeruddin; Richard H Friend; Michael Graetzel; M Ibrahim Dar

doi:10.1021/acs.jpclett.0c02791

Minimizing the Trade-Off between Photocurrent and Photovoltage in Triple-Cation Mixed-Halide Perovskite Solar Cells

J Phys Chem Lett. 2020 Dec 3;11(23):10188-10195. doi: 10.1021/acs.jpclett.0c02791. Epub 2020 Nov 18.

Authors

Thomas Baumeler¹, Neha Arora^{1

2}, Alexander Hinderhofer³, Seckin Akin^{1

4}, Alessandro Greco³, Mojtaba Abdi-Jalebi², Ravichandran Shivanna², Ryusuke Uchida^{1

5}, Yuhang Liu¹, Frank Schreiber³, Shaik M Zakeeruddin¹, Richard H Friend², Michael Graetzel¹, M Ibrahim Dar^{1

2}

Affiliations

¹ Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland.
² Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
³ Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany.
⁴ Department of Metallurgical and Materials Engineering, Karamanoglu Mehmetbey University, 70100 Karaman, Turkey.
⁵ Institute for Energy and Material/Food Resources, Technology Innovation Division, Panasonic Corporation, 3-1-1 Yagumo-Naka-machi, Moriguchi City, Osaka 570-8501, Japan.

PMID: 33205977
DOI: 10.1021/acs.jpclett.0c02791

Abstract

Its lower bandgap makes formamidinium lead iodide (FAPbI₃) a more suitable candidate for single-junction solar cells than pure methylammonium lead iodide (MAPbI₃). However, its structural and thermodynamic stability is improved by introducing a significant amount of MA and bromide, both of which increase the bandgap and amplify trade-off between the photocurrent and photovoltage. Here, we simultaneously stabilized FAPbI₃ into a cubic lattice and minimized the formation of photoinactive phases such as hexagonal FAPbI₃ and PbI₂ by introducing 5% MAPbBr₃, as revealed by synchrotron X-ray scattering. We were able to stabilize the composition (FA_0.95MA_0.05Cs_0.05)Pb(I_0.95Br_0.05)₃, which exhibits a minimal trade-off between the photocurrent and photovoltage. This material shows low energetic disorder and improved charge-carrier dynamics as revealed by photothermal deflection spectroscopy (PDS) and transient absorption spectroscopy (TAS), respectively. This allowed the fabrication of operationally stable perovskite solar cells yielding reproducible efficiencies approaching 22%.