Block Copolymer Stabilized Liquid Nanodroplets Facilitate Efficient Triplet Fusion-Based Photon Upconversion in Solid...

Area of Science:

• Photophysical processes
• Materials science
• Polymer chemistry

Background:

• Photon upconversion (PUC) via sensitized triplet-triplet annihilation (TTA) typically requires high molecular mobility, limiting its application in solid-state systems.
• Efficient energy transfer in solid polymers necessitates specific architectures, such as liquid domains or reduced intermolecular dye distances for exciton migration.
• Existing methods often struggle to achieve high PUC efficiency in solid matrices due to restricted dye mobility and energy transfer limitations.

Purpose of the Study:

• To introduce novel nanostructured polymer materials that facilitate efficient solid-state photon upconversion.
• To combine liquid upconverting domains with reduced intermolecular dye distances within a single material architecture.
• To achieve high triplet-triplet annihilation (TTA) efficiency in a solid polymer matrix.

Main Methods:

• Fabrication of glassy nanostructured polymer systems containing liquid upconverting nanodroplets stabilized by block copolymer surfactants.
• Incorporation of emitter dyes that concentrate within the liquid nanodomains.
• Utilizing a facile, one-step protocol under ambient conditions for material synthesis.

Main Results:

• The nanostructured materials successfully combine liquid upconverting domains and reduced dye intermolecular distances.
• Dye concentration within the liquid domains facilitates hopping-mediated energy transfer (ET) and triplet-triplet annihilation (TTA).
• Achieved a significant upconversion efficiency of approximately 20% in the solid-state nanostructured polymer system.

Conclusions:

• The developed nanostructured polymer systems offer a viable strategy for efficient solid-state photon upconversion.
• Combining liquid domains and proximity-induced triplet hopping enhances energy transfer and PUC efficiency.
• This facile one-step fabrication method provides a promising route for advanced optical materials.