Breaking the Zero Dimensional Illusion in Te(IV) Metal Halide Hybrids via Electronic Dimensionality Control

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photophysics

Background:

• Zero-dimensional (0D) metal halide hybrids (MHHs) with ns² metal ions are promising solid-state emitters.
• Photoluminescence quantum yields (PLQYs) in these materials often show unpredictable variations, hindering rational design.

Purpose of the Study:

• To elucidate the factors governing emissivity in 0D ns² metal halide hybrids.
• To establish a structure-property relationship for designing high-performance luminescent MHHs.

Main Methods:

• Synthesis and characterization of a series of 0D Te(IV)-based hybrids (A₂TeCl₆).
• Single-crystal X-ray diffraction, Hirshfeld surface analysis, and Voronoi polyhedral mapping.
• Density Functional Theory (DFT) calculations to study excited-state relaxation.

Main Results:

• Cation-dependent crystal packing, not local octahedral distortion, drives differences in PLQY and lifetimes.
• Interoctahedral halide-halide distance is identified as a key structural descriptor for exciton delocalization and nonradiative quenching.
• DFT calculations successfully reproduced the experimental emissivity trends.

Conclusions:

• A clear structure-property relationship for 0D ns² MHHs is established.
• Interoctahedral halide-halide distance serves as a predictive metric for luminescence properties.
• This work provides a framework for designing efficient MHH-based luminescent materials.