Study on NIR optical rewritable film based on dithienylethene and upconversion nanocrystals

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Upconversion nanoparticles (UCNPs) offer unique optical properties for advanced applications.
• Photochromic materials like dithienylethene (DTE) are crucial for optical data storage.
• Integrating UCNPs with photochromic materials can lead to novel functionalities.

Purpose of the Study:

• To synthesize Tm3+ and Yb3+ codoped NaYF4 upconversion nanoparticles (UCNPs).
• To develop a NIR optical rewritable film using these UCNPs and DTE for optical storage.
• To investigate the performance and durability of the DTE photochromic reaction induced by UCNP fluorescence.

Main Methods:

• Solvothermal synthesis of Tm3+ and Yb3+ codoped NaYF4 UCNPs.
• Incorporation of UCNPs and DTE into a film for optical storage.
• Utilizing multiphoton upconversion fluorescence for photochromic switching.
• Testing write/erase cycles using NIR and green irradiation.

Main Results:

• Intense ultraviolet (UV) fluorescence was achieved from the synthesized NaYF4 UCNPs.
• The UCNP-DTE film demonstrated optical rewritable storage capabilities.
• The photochromic DTE exhibited no significant fatigue after repeated write/erase cycles.
• The system relies on UV light generated by UCNPs to trigger DTE's photochromic reaction.

Conclusions:

• Tm3+ and Yb3+ codoped NaYF4 UCNPs can generate intense UV fluorescence suitable for optical storage applications.
• The developed NIR optical rewritable film utilizing UCNPs and DTE is a viable technology for optical data storage.
• The DTE component shows excellent stability and durability for repeated optical data writing and erasing.