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Exciton–exciton interactions are fundamental to the light-emitting properties of semiconductors, influencing applications from lasers to quantum light sources. In this study, we investigate the spectroscopic signatures and binding energy of biexcitons in a metal halide two-dimensional Ruddlesden–Popper structure, which is known for hosting distinct excitonic resonances (X1 and X2) with unique lattice coupling. These multiple resonances enable the formation of both self- and cross-coupled biexcitons (mixed biexcitons). Using three spectroscopic techniques—photoluminescence and two variations of two-dimensional electronic spectroscopy (2DES)—we map coherent one-quantum and two-quantum correlations to gain deeper insight into the biexciton characteristics. While PL spectroscopy is hindered by spectral broadening and reabsorption, 2DES provides a more accurate characterization, revealing multiple biexciton states and uncovering the mixed biexciton species arising from exciton cross coupling. These findings highlight the importance of advanced spectroscopic approaches in accurately determining biexciton binding energies and offer new perspectives on many-body interactions in exciton–polarons within layered perovskites.
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Exciton Dynamics in Layered Halide Perovskite Light‐Emitting Diodes
Abstract Layered halide perovskites have garnered significant interest due to their exceptional optoelectronic properties and great promises in light‐emitting applications. Achieving high‐performance perovskite light‐emitting diodes (PeLEDs) requires a deep understanding of exciton dynamics in these materials. This review begins with a fundamental overview of the structural and photophysical properties of layered halide perovskites, then delves into the importance of dimensionality control and cascade energy transfer in quasi‐2D PeLEDs. In the second half of the review, more complex exciton dynamics, such as multiexciton processes and triplet exciton dynamics, from the perspective of LEDs are explored. Through this comprehensive review, an in‐depth understanding of the critical aspects of exciton dynamics in layered halide perovskites and their impacts on future research and technological advancements for layered halide PeLEDs is provided.
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- PAR ID:
- 10563310
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Materials
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/adma.202411998
