Pressure-Engineered Photoluminescence Tuning in Zero-Dimensional Lead Bromide Trimer Clusters

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photophysics

Background:

• Zero-dimensional (0D) hybrid metal halides are excellent candidates for light-emitting applications.
• Controlling their photoluminescence properties through structural design remains a significant challenge.

Purpose of the Study:

• To investigate the effect of high pressure on the self-trapped exciton (STE) emission of 0D (bmpy)9[ZnBr4]2[Pb3Br11].
• To explore the potential for tuning the photoluminescence properties, including achieving white-light emission.

Main Methods:

• Application of high pressure to a specific 0D hybrid metal halide, (bmpy)9[ZnBr4]2[Pb3Br11].
• Analysis of structural changes and their correlation with photoluminescence spectral shifts.

Main Results:

• Compression induced simultaneous contraction and distortion of the photoactive [Pb3Br11]5- units.
• Emission color was tuned from yellow-green to cyan due to altered STE emission equilibria.
• Sufficient compression led to deeper STE states, resulting in unprecedented broadband white-light emission.

Conclusions:

• High pressure is an effective tool for manipulating the optical properties of 0D hybrid metal halides.
• The study provides new insights into the mechanism of STE emission and structure-property relationships in these materials.