Efficient Interlayer Exciton Transport in Two-Dimensional Metal-Halide Perovskites.

Magdaleno, Alvaro J.; Seitz, Michael; Frising, Michel; Cruz, Ana Herranz de la; Fernández‐Domínguez, Antonio I.; Prins, Ferry

doi:10.26434/chemrxiv.13073153.v1

Cited by 2 publications

(2 citation statements)

References 34 publications

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“…Fundamentally, this discovery of exciton delocalization, and thus strong inter-QW electronic coupling, provides a novel understanding of the physical processes behind these inter-QW processes, which were previously ascribed to various independent weak-coupling mechanisms. It pieces together the previous reports of various inter-QW interactions (i.e., interwell charge transfer excitons, inter-QW biexcitonic interactions, interlayer exciton diffusion, etc.). Furthermore, such Dexter-like coherent energy transfer uncovered by our model is expected to be spin-preserving.…”

Section: Discussionsupporting

confidence: 90%

The Physics of Interlayer Exciton Delocalization in Ruddlesden–Popper Lead Halide Perovskites

et al. 2020

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Two-dimensional (2D) lead halide Ruddlesden–Popper perovskites (RPP) have recently emerged as a prospective material system for optoelectronic applications. Their self-assembled multi quantum-well structure gives rise to the novel interwell energy funnelling phenomenon, which is of broad interests for photovoltaics, light-emission applications, and emerging technologies (e.g., spintronics). Herein, we develop a realistic finite quantum-well superlattice model that corroborates the hypothesis of exciton delocalization across different quantum-wells in RPP. Such delocalization leads to a sub-50 fs coherent energy transfer between adjacent wells, with the efficiency depending on the RPP phase matching and the organic large cation barrier lengths. Our approach provides a coherent and comprehensive account for both steady-state and transient dynamical experimental results in RPPs. Importantly, these findings pave the way for a deeper understanding of these systems, as a cornerstone crucial for establishing material design rules to realize efficient RPP-based devices.

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Section: Discussionsupporting

confidence: 90%

The Physics of Interlayer Exciton Delocalization in Ruddlesden–Popper Lead Halide Perovskites

et al. 2020

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“…On the other hand, the large lateral sizes of the grains allow faster in-plane diffusion based on the intragrain dynamics (DX,lateral = 0.04 cm 2 s -1 ), as shown in Figure 5d. Such an anisotropy of DX,lateral /DX,verti > 10 we measure for a thin-film 2D perovskite is much bigger than the recently reported values obtained by directly measuring bulk single crystals, such as 3.7 for (PEA)2PbI4 (PEA: phenethylammonium) 35 and 1.5 for 4AMP-MAPb2I7 (4AMP: 4-(aminomethyl)piperidinium; MA: methylammonium) 36 . Thin-film 2D perovskite stacks are becoming popular in many applications such as solar cells, LEDs, and lasers, based on their high radiation efficiency and stability.…”

Section: Anisotropic Exciton Diffusion For In-plane Stacked 2d Perovs...contrasting

confidence: 68%

Efficient vertical charge transport in polycrystalline halide perovskites revealed by four-dimensional tracking of charge carriers

et al. 2022

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Fast diffusion of charge carriers is crucial for efficient charge collection within their lifetime in perovskite solar cells. While lateral transient photoluminescence microscopies have been popularly used to characterise charge diffusion in perovskites, there exists a discrepancy between low diffusion coefficients measured to be on the order of 10 -2 cm 2 s -1 and near-unity charge collection efficiencies achieved in practical solar cells. Here, we reveal hidden microscopic dynamics in halide perovskites through four-dimensional (4D -x, y, z, t) tracking of charge carriers. First, we investigate a method for characterising out-of-plane diffusion of charge carriers applicable to general semiconductors by exploiting the effect of optical self-filtering on external photoluminescence spectra. By combining this approach with confocal microscopy, we discover a strong local heterogeneity of vertical charge diffusivities varying from 0.006 to 0.3 cm 2 s -1 in a 3D perovskite film, arising from the difference between intragrain and intergrain diffusion. By contrast, conventional in-plane measurements yield a diffusivity of only 0.02 cm 2 s -1 in the same film, which is limited by intergrain charge transport. In the out-of-plane direction across the film thickness, our 4D tracking visualises that most charge carriers are efficiently transported through the direct intragrain pathways or via indirect detours through nearby areas with a fast diffusion. Finally, our technique also quantifies significant anisotropy of exciton diffusion in a vertically stacked 2D perovskite film. The observed anisotropy and heterogeneity of charge carrier diffusion in perovskites rationalize their high performance shown in real devices. Our work also foresees that further control of polycrystal growth will enable solar cells with micrometres-thick perovskites to achieve both long optical path length and efficient charge collection simultaneously.

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Efficient Interlayer Exciton Transport in Two-Dimensional Metal-Halide Perovskites.

Cited by 2 publications

References 34 publications

The Physics of Interlayer Exciton Delocalization in Ruddlesden–Popper Lead Halide Perovskites

The Physics of Interlayer Exciton Delocalization in Ruddlesden–Popper Lead Halide Perovskites

Efficient vertical charge transport in polycrystalline halide perovskites revealed by four-dimensional tracking of charge carriers

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