Perspective: Exciton polarons in two-dimensional hybrid metal-halide perovskites

Bibliographic Details
Title: Perspective: Exciton polarons in two-dimensional hybrid metal-halide perovskites
Authors: Kandada, Ajay Ram Srimath, Silva, Carlos
Source: J. Phys. Chem. Lett. 2020, 11, 3173-3184
Publication Year: 2019
Collection: Condensed Matter
Physics (Other)
Subject Terms: Condensed Matter - Materials Science, Physics - Chemical Physics
More Details: While polarons --- charges bound to a lattice deformation induced by electron-phonon coupling --- are primary photoexcitations at room temperature in bulk metal-halide hybrid organic-inorganic perovskites (HOIP), excitons --- Coulomb-bound el\-ectron-hole pairs --- are the stable quasi-particles in their two-dimensional (2D) analogues. Here we address the fundamental question: are polaronic effects consequential for excitons in 2D-HIOPs? Based on our recent work, we argue that polaronic effects are manifested intrinsically in the exciton spectral structure, which is comprised of multiple non-degenerate resonances with constant inter-peak energy spacing. We highlight our own measurements of population and dephasing dynamics that point to the apparently deterministic role of polaronic effects in excitonic properties. We contend that an interplay of long-range and short-range exciton-lattice couplings give rise to exciton polarons, a character that fundamentally establishes their effective mass and radius, and consequently, their quantum dynamics. Finally, we highlight opportunities for the community to develop the rigorous description of exciton polarons in 2D-HIOPs to advance their fundamental understanding as model systems for condensed-phase materials in which lattice-mediated correlations are fundamental to their physical properties.
Comment: Corrected author name in V2
Document Type: Working Paper
DOI: 10.1021/acs.jpclett.9b02342
Access URL: http://arxiv.org/abs/1908.03909
Accession Number: edsarx.1908.03909
Database: arXiv
More Details
DOI:10.1021/acs.jpclett.9b02342