Host-Guest Engineering of MOF-808 for Random Lasing and Solid-State Emission.

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Fluorescent organic dyes suffer from photobleaching and aggregation-caused quenching, limiting their solid-state and high-power photonics applications.
• Metal-organic frameworks (MOFs) offer porous structures ideal for stabilizing guest molecules and enhancing their performance.

Purpose of the Study:

• To investigate the optical properties of rhodamine B and coumarin 343 dyes encapsulated within Zr-based MOF-808.
• To assess the potential of MOF-dye composites for solid-state luminescence and random lasing applications.

Main Methods:

• Encapsulation of rhodamine B and coumarin 343 dyes within MOF-808 cavities.
• Characterization of dye-MOF interactions in both solid-state and solution.
• Evaluation of random lasing performance, including threshold and spectral narrowing, in dye-MOF systems.
• Fabrication of polymeric thin films incorporating MOF-808 nanoparticles and dyes.

Main Results:

• Dye encapsulation in MOF-808 prevented aggregation-induced quenching, enabling solid-state luminescence and applications like fingerprint detection.
• MOF-808 nanoparticles enhanced random lasing in solution by acting as scatterers, narrowing emission spectra and reducing the lasing threshold.
• Optimal MOF concentration and excitation intensity were found to minimize lasing threshold and bandwidth.
• Incorporation into polymeric thin films halved the lasing threshold, demonstrating potential for portable lasing devices.

Conclusions:

• Embedding fluorescent dyes in MOF-808 enhances their stability and optical properties, overcoming limitations of aggregation-caused quenching.
• MOF-808 serves as an effective platform for improving dye-based solid-state emission and random lasing.
• The developed MOF-dye composite materials show promise for advanced photonic and sensing applications, including portable lasers.