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Dataset of "The Impact of Spacer Size on Charge Transfer Excitons in Dion-Jacobson and Ruddlesden-Popper Layered Hybrid Perovskites"

Masaud Hassan S Almalki, George Cameron Fish, Michael Graetzel, Jacques-Edouard Moser, Lukas Pfeifer, Aaron Tomas Terpstra

This dataset underpins the following article published in the Journal of Physical Chemistry Letters: "The Impact of Spacer Size on Charge Transfer Excitons in Dion-Jacobson and Ruddlesden-Popper Layered Hybrid Perovskites" DOI: 10.1021/acs.jpclett.3c01125 The dataset contains steady state absorption (UV/Vis), transient absorption (TA) and electroabsorption (EA) data acquired from experiments on 2D perovskites incorporating different organic spacers. The dataset also includes data acquired from temperature dependent measurements. The transient absorption data has been treated using a home-written matlab script in order to correct for the chirp.

EPFL Infoscience2023

Surface Passivation of FAPbI3-Rich Perovskite with Cesium Iodide Outperforms Bulk Incorporation

Essa Awadh R Alharbi, Thomas Paul Baumeler, Brian Irving Carlsen, Felix Thomas Eickemeyer, George Cameron Fish, Jing Gao, Michael Graetzel, Mounir Driss Mensi, Jacques-Edouard Moser, Lukas Pfeifer, Kevin Sivula, Jun Ho Yum, Shaik Mohammed Zakeeruddin

Metal halide perovskites (MHPs) have shown an incredible increase in efficiency, reaching as high as 25.7%, which now competes with traditional photovoltaic technologies. Herein, we excluded CsX and RbX (X = I–, Br–, Cl–), the most commonly used cations to stabilize α-FAPbI3, from the bulk of perovskite thin films and applied them on the surface as passivation agents. Extensive device optimization led to a power conversion efficiency (PCE) of 24.1% with a high fill factor (FF) of 82.2% upon passivation with CsI. We investigated in depth the effect of CsI passivation on structural and optoelectronic properties using X-ray diffraction (XRD), angle-resolved X-ray photoelectron spectroscopy (ARXPS), Kelvin probe force microscopy (KPFM), time-resolved photoluminescence (TRPL), photoluminescence quantum yield (PLQY), and electroabsorption spectroscopy (TREAS). Furthermore, passivated devices exhibit enhanced operational stability, with optimized passivation with CsI leading to a retention of ∼90% of the initial PCE under 1 sun illumination with maximum power point tracking for 600 h.

2023

The Impact of Spacer Size on Charge Transfer Excitons in Dion–Jacobson and Ruddlesden–Popper Layered Hybrid Perovskites

Masaud Hassan S Almalki, Loï Charles Carbone, Algirdas Ducinskas, George Cameron Fish, Michael Graetzel, Jovana Milic, Jacques-Edouard Moser, Lukas Pfeifer, Aaron Tomas Terpstra

Organic materials can tune the optical properties in layered (2D) hybrid perovskites, although their impact on photophysics is often overlooked. Here, we use transient absorption spectroscopy to probe the Dion−Jacobson (DJ) and Ruddlesden−Popper (RP) 2D perovskite phases. We show the formation of charge transfer excitons in DJ phases, resulting in a photoinduced Stark effect which is shown to be dependent on the spacer size. By using electroabsorption spectroscopy, we quantify the strength of the photoinduced electric field, while temperature-dependent measurements demonstrate new features in the transient spectra of RP phases at low temperatures resulting from the quantum-confined Stark effect. This study reveals the impact of spacer size and perovskite phase configuration on charge transfer excitons in 2D perovskites of interest to their advanced material design.

2023