Lanthanide-Induced Photoluminescence in Lead-Free Cs2AgBiBr6 Bulk Perovskite: Insights from Optical and Theoretical Investigations

Fabian Schmitz; Kunping Guo; Jonas Horn; Roberto Sorrentino; Gioele Conforto; Francesco Lamberti; Rosaria Brescia; Filippo Drago; Mirko Prato; Zhubing He; Umberto Giovanella; Franco Cacialli; Derck Schlettwein; Daniele Meggiolaro; Teresa Gatti

doi:10.1021/acs.jpclett.0c02317

Lanthanide-Induced Photoluminescence in Lead-Free Cs₂AgBiBr₆ Bulk Perovskite: Insights from Optical and Theoretical Investigations

J Phys Chem Lett. 2020 Oct 15;11(20):8893-8900. doi: 10.1021/acs.jpclett.0c02317. Epub 2020 Oct 6.

Authors

Fabian Schmitz^{1

2}, Kunping Guo³, Jonas Horn^{1

4}, Roberto Sorrentino⁵, Gioele Conforto^{2

4}, Francesco Lamberti⁶, Rosaria Brescia⁷, Filippo Drago⁸, Mirko Prato⁸, Zhubing He⁹, Umberto Giovanella⁵, Franco Cacialli³, Derck Schlettwein^{1

4}, Daniele Meggiolaro¹⁰, Teresa Gatti^{1

2}

Affiliations

¹ Center for Materials Research (LaMa), Justus Liebig University, Heinrich Buff Ring 16, 35392 Giessen, Germany.
² Institute of Physical Chemistry, Justus Liebig University, Heinrich Buff Ring 17, 35392 Giessen, Germany.
³ Department of Physics and Astronomy and London Center for Nanotechnology, University College London, WC1E 6BT London, United Kingdom.
⁴ Institute of Applied Physics, Justus Liebig University, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
⁵ Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta", Via Corti 12, 20133 Milano, Italy.
⁶ Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy.
⁷ Electron Microscopy Facility, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy.
⁸ Materials Characterization Facility, Istituto Italiano di Tecnologiass, via Morego 30, 16163 Genova, Italy.
⁹ Department of Materials Science and Engineering, Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation, Southern University of Science and Technology, No. 1088, Xueyuan Rd., 518055 Shenzhen, Guangdong, China.
¹⁰ Computational Laboratory for Hybrid/Organic Photovoltaics, Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta", Via Elce di Sotto 8, 06123 Perugia, Italy.

PMID: 32996314
DOI: 10.1021/acs.jpclett.0c02317

Abstract

Emphasis was recently placed on the Cs₂AgBiBr₆ double perovskite as a possible candidate to substitute toxic lead in metal halide perovskites. However, its poor light-emissive features currently make it unsuitable for solid-state lighting. Lanthanide doping is an established strategy to implement luminescence in poorly emissive materials, with the additional advantage of fine-tuning the emission wavelength. We discuss here the impact of Eu and Yb doping on the optical properties of Cs₂AgBiBr₆ thin films, obtained from the solution processing of hydrothermally synthesized bulk crystalline powders, by combining experiments and density functional theory calculations. Eu(III) incorporation does not lead to the characteristic ⁵D₀ → ⁷F₂ emission feature at 2 eV, while only a weak trap-assisted sub-band gap radiative emission is reported. Oppositely, we demonstrate that incorporated Yb(III) leads to an intense and exclusive photoluminescence emission in the near-infrared as a result of the efficient sensitization of the lanthanide ²F_5/2 → ²F_7/2 transition.