Determining Chemical Microheterogeneity from the Analysis of Absorption and Luminescence Transient Signals

Area of Science:

• Materials Science
• Physical Chemistry
• Spectroscopy

Background:

• Chemical microheterogeneity is crucial in advanced materials like soft and high-entropy materials.
• Understanding microheterogeneity aids in designing systems with tailored properties.

Purpose of the Study:

• To quantitatively characterize chemical microheterogeneity in photochromic and metal oxide solid solution systems.
• To compare different analytical methods for assessing microheterogeneity.

Main Methods:

• Utilized time-resolved absorption and luminescence spectroscopy after photoexcitation.
• Analyzed transient spectroscopic signals using Maximum Entropy Method (MEM) for polyexponential functions.
• Applied discrete exponential, Kohlrausch, and Becquerel functions with the Levenberg-Marquardt algorithm.

Main Results:

• Demonstrated quantitative characterization of chemical microheterogeneity through comparative analysis of fitting functions and algorithms.
• Showcased transformation of photochromic samples into multistate systems for enhanced information encoding.
• Revealed that microheterogeneous photocatalysts possess structural defects leading to multiple active sites and improved catalytic activity.

Conclusions:

• Chemical microheterogeneity significantly impacts material properties, enabling advanced functionalities.
• The employed spectroscopic and analytical methods provide robust tools for microheterogeneity characterization.
• This research highlights the practical applications of controlling microheterogeneity in materials science and catalysis.