Interplay of dielectric confinement and charge–phonon interactions in layered perovskites

Determine how dielectric confinement and charge–phonon interactions together influence the excited-state properties of two-dimensional layered lead halide perovskites.

Background

Two-dimensional layered lead halide perovskites exhibit strong excitonic effects due to dielectric confinement from polar inorganic slabs and less polar organic ligands. Separately, polaronic physics arising from charge–phonon coupling has been extensively studied in three-dimensional perovskites. Despite this, the combined impact of dielectric confinement and electron–phonon interactions on the excited-state properties of layered perovskites has not been fully clarified and represents a key uncertainty motivating the study.

This problem concerns establishing a comprehensive understanding of how these two mechanisms jointly shape exciton energetics and related photophysical behavior in layered hybrid organic–inorganic perovskite structures.

References

While the role of dielectric confinement has been studied for two-dimensional materials, and the influence of polaronic physics has been probed extensively in three-dimensional perovskites, it remains unclear how these two effects together influence the excited state properties of layered perovskites.

— On the interplay of electronic and lattice screening on exciton binding in two-dimensional lead halide perovskites  (2407.08173 - Rana et al., 2024) in Introduction (first paragraph), Page 1

Recent perspectives have highlighted that the interpretation of hot-phonon bottlenecks in halide perovskites remains controversial, underscoring the importance of complementary approaches capable of directly probing carrier–phonon interactions under device-relevant operating conditions.

— Operando Raman probing of mode selective electron phonon coupling in two dimensional halide perovskites  (2608.18513 - Paul et al., 19 Aug 2026) in Discussion, Section 3, “Phonon lifetime in 2D halide perovskites,” p. 20

Globally, the mode has an unclear effect onμ, though we observe that has a large local impact on the band structure for (EAOH)2PbI4.

— Structural tuning of reduced exciton mass in layered HOIP compounds: Causation vs. correlation  (2609.04558 - Burkholder et al., 3 Sep 2026) in Section 3.5, discussion of Figure 8