Intrinsic Cool White-to-Deep Blue Emission in a Mechanically Tunable Zero-Dimensional Zirconium Halide Phosphor

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photophysics

Background:

• Single-component white-light emitters are highly sought after but remain rare, particularly in metal halide perovskites.
• Conventional white-light generation often involves combining multiple phosphors, leading to efficiency losses.
• Developing intrinsic white-light emitters is crucial for advancing lighting technologies.

Purpose of the Study:

• To introduce a novel zero-dimensional zirconium halide phosphor, (PPh4)2ZrCl6, for intrinsic cool-white light emission.
• To investigate the photoluminescent properties and stimuli-responsive behavior of this material.
• To explore its potential as a single-component white-light emitter.

Main Methods:

• Synthesis and characterization of the zero-dimensional zirconium halide phosphor, (PPh4)2ZrCl6.
• Photoluminescence spectroscopy to analyze emission spectra, exciton binding energy, and self-trapped exciton (STE) dynamics.
• Application of external pressure (up to 9 GPa) and mechanical force to study emission tuning and stimuli-responsive properties.

Main Results:

• (PPh4)2ZrCl6 exhibits intrinsic cool-white-light emission with CIE coordinates (0.33, 0.33) and a CCT of 5609 K.
• Strong exciton binding energy (358.7 meV) and dual emission bands from singlet and triplet STEs were observed.
• Emission color shifts from cool white to deep blue under mechanical stress, altering CIE coordinates to (0.19, 0.18).

Conclusions:

• Single crystals of (PPh4)2ZrCl6 are promising single-component white-light phosphors with tunable emission.
• The material's response to pressure and mechanical force offers insights into stimuli-responsive photoluminescent behavior.
• This work paves the way for new single-component emitters and advanced functional materials.