Phonon-bottleneck enhanced exciton emission in 2D perovskites

Joshua J. P. Thompson; Mateusz Dyksik; Paulina Peksa; Katarzyna Posmyk; Ambjörn Joki; Raul Perea-Causin; Paul Erhart; Michał Baranowski; Maria Antonietta Loi; Paulina Plochocka; Ermin Malic

arXiv · 2312.10688

Phonon-bottleneck enhanced exciton emission in 2D perovskites

Joshua J. P. Thompson·Mateusz Dyksik·Paulina Peksa·Katarzyna Posmyk·Ambjörn Joki·Raul Perea-Causin·Paul Erhart·Michał Baranowski·Maria Antonietta Loi·Paulina Plochocka·Ermin Malic

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Abstract

Layered halide perovskites exhibit remarkable optoelectronic properties and technological promise, driven by strongly bound excitons. The interplay of spin-orbit and exchange coupling creates a rich excitonic landscape, determining their optical signatures and exciton dynamics. Despite the dark excitonic ground state, surprisingly efficient emission from higher-energy bright states has puzzled the scientific community, sparking debates on relaxation mechanisms. Combining low-temperature magneto-optical measurements with sophisticated many-particle theory, we elucidate the origin of the bright exciton emission in perovskites by tracking the thermalization of dark and bright excitons under a magnetic field. We clearly attribute the unexpectedly high emission to a pronounced phonon-bottleneck effect, considerably slowing down the relaxation towards the energetically lowest dark states. We demonstrate that this bottleneck can be tuned by manipulating the bright-dark energy splitting and optical phonon energies, offering valuable insights and strategies for controlling exciton emission in layered perovskite materials that is crucial for optoelectronics applications.

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Joshua J. P. Thompson, Mateusz Dyksik, Paulina Peksa, Katarzyna Posmyk, Ambjörn Joki, Raul Perea-Causin, Paul Erhart, Michał Baranowski, Maria Antonietta Loi, Paulina Plochocka, Ermin Malic. 2023-12-17. Phonon-bottleneck enhanced exciton emission in 2D perovskites. https://arxiv.org/abs/2312.10688

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