Energy transfer engineering for programmable fluorescence dynamics in CsPbBr₃ perovskite: Toward multimode...

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Smart fluorescent materials are crucial for anti-counterfeiting.
• Tunable fluorescence in response to stimuli is highly desirable.
• Perovskite nanocrystals offer unique optical properties.

Purpose of the Study:

• To develop a photoresponsive fluorescent material (PRFM) for advanced anti-counterfeiting applications.
• To integrate perovskite CsPbBr3 with photochromic spiropyran (SPD) in PMMA.
• To achieve multimode fluorescence outputs through external stimuli.

Main Methods:

• Integration of CsPbBr3 nanocrystals and SPD within a PMMA matrix.
• Characterization of fluorescence properties under different excitation wavelengths (blue, UV, visible light).
• Investigation of energy transfer mechanisms using fluorescence decay spectra and theoretical calculations.

Main Results:

• The developed material, SPD-CsPbBr3@PMMA, exhibits stable green fluorescence under blue-light excitation.
• UV irradiation induces SPD isomerization, resulting in red fluorescence due to efficient energy transfer from CsPbBr3.
• Visible light restores the original green fluorescence, demonstrating reversible fluorescence switching.
• Multimode fluorescence changes were observed under room, blue, and UV light, enabling complex anti-counterfeiting strategies.

Conclusions:

• The study successfully developed a novel multimode PRFM with tunable fluorescence.
• Efficient energy transfer between CsPbBr3 and open-ring SPD is key to fluorescence modulation.
• The material shows significant potential for advanced information anti-counterfeiting and security applications.