A Sodium Metal-Organic Framework with Deep Blue Room-Temperature Phosphorescence

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photophysics

Background:

• Developing stable, room-temperature phosphorescent materials, especially in the blue spectrum, presents significant challenges.
• Environmental adaptability is crucial for practical applications of phosphorescent materials.

Purpose of the Study:

• To synthesize and characterize a novel sodium-based metal-organic framework (MOF) for room-temperature blue long afterglow phosphorescence.
• To investigate the structural and electronic properties contributing to the material's luminescence and stability.

Main Methods:

• Synthesis of a sodium-based MOF using Na+ and 1H-1,2,4-triazole-3,5-dicarboxylic acid.
• Characterization of photoluminescence properties, including afterglow lifetime and color.
• First-principles time-dependent density functional theory (TD-DFT) calculations.

Main Results:

• The Na-based MOF exhibits long-lived (378.9 ms) deep blue room-temperature phosphorescence with a visible afterglow lasting 3-6 seconds.
• The material demonstrates stability in different gas atmospheres, with unchanged phosphor lifetime and residual color.
• TD-DFT calculations indicate that the rigid MOF structure suppresses non-radiative decay and enhances radiative decay rates.

Conclusions:

• The constructed Na-based MOF is a promising candidate for stable, long-lived blue room-temperature phosphorescent applications.
• The rigid framework effectively protects the phosphorescent organic ligands, ensuring environmental stability.
• Suppression of non-radiative decay pathways is key to achieving enhanced phosphorescence performance.