Precise description of local structure and nature (dynamic vs static) of nanodomains in hybrid halide perovskites

Establish a precise, comprehensive description of the local crystallographic structure in hybrid organic–inorganic lead halide perovskites and ascertain whether the observed nanoscale domains are dynamic or static.

Background

Short-range correlations in hybrid halide perovskites are thought to strongly influence macroscopic optoelectronic properties, yet multiple, often conflicting local-structure models have been proposed (e.g., polymorphous networks, B-site off-centering, embedded orthorhombic phases, static in-/anti-phase octahedral correlations, dynamic noncentrosymmetric domains, and two-dimensional octahedral sheets).

The authors explicitly state that a precise description has not yet been established and that there is no consensus on whether these nanodomains are dynamic or static—an uncertainty that their work seeks to address by correlating experimental diffuse scattering with simulations.

References

The precise description of the local structure in these materials has not yet been established and currently ranges from polymorphous networks [11], B-site off-centering correlations [12], to local orthorhombic phases embedded in average tetragonal and cubic global structures [13, 14], static in-phase and anti-phase octahedral correlations [15], noncentrosymmetric dynamic local nanodomains [16] and two-dimensional dynamic octahedral sheets [17, 18] with no consensus on whether these local nanodomains are dynamic or static.

— Dynamic Nanodomains Dictate Macroscopic Properties in Lead Halide Perovskites  (2404.14598 - Dubajic et al., 2024) in Main text, Introduction (first page)

Three questions remain genuinely open. First, the microscopic identity of the central peak: relaxational tilt hopping, strongly overdamped soft modes, and coupled cation-cage dynamics produce similar quasielastic signatures, and their disentanglement — for instance by comparing polarization selection rules and momentum structure across the Cs/MA/FA series — is incomplete.

— Band-like Carriers in a Soft, Anharmonic Lattice: Lead-Halide Perovskites  (2608.28104 - Lee et al., 28 Aug 2026) in Section 4.6, Open questions

Whether dynamical Rashba has any observable that cannot be mimicked by static local symmetry breaking in the polymorphous ensemble — a sharper theoretical question than is usually acknowledged.

— Band-like Carriers in a Soft, Anharmonic Lattice: Lead-Halide Perovskites  (2608.28104 - Lee et al., 28 Aug 2026) in Section 11.4, Open questions