Halogen‐Driven Trade‐Off Between Humidity and Thermal Stability in Zero‐Dimensional Hybrid Manganese Halides for Dual‐Stimulus Encryption
Year: 2026
Type: article
Abstract: ABSTRACT Zero‐dimensional (0D) hybrid manganese halides are attractive lead‐free luminescent materials, yet the simultaneous demands for moisture and thermal stability pose a fundamental challenge. Here we demonstrate a halogen‐driven trade‐off between humidity and thermal stability in (BrPhTMN) 2 MnX 4 (X = Cl, Br, I) with a non‐hydrogen‐bonding cation. Replacing Cl with I dramatically increases the photoluminescence quantum yield (from 20.2% to 84.3%) but drastically reduces humidity resistance at 90% relative humidity (RH) (from ∼51 h for the bromide to <14 min for the iodide). Remarkably, the thermal stability trend is reversed: the iodide shows enhanced emission at 430 K, whereas the chloride is heavily quenched. This paradoxical thermal robustness of the iodide, despite its large electron–phonon coupling (Huang–Rhys factor S = 4.43), can be rationalized by the energy‐gap law for multiphonon relaxation. Raman spectroscopy reveals an exceptionally low Mn–I phonon frequency (111 cm −1 ), which exponentially suppresses multiphonon non‐radiative decay, effectively closing the non‐radiative channel even under strong coupling. Exploiting these orthogonal stabilities, we construct a dual‐stimulus encryption device responsive to specific humidity‐heat sequences. This work establishes a design principle for anti‐thermal‐quenching luminescent materials and opens avenues for advanced stimulus‐responsive systems.
Source: Laser & Photonics Review
DOI: 10.1002/lpor.72086
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7222791103