3 years ago

New Bichromophoric Triplet Photosensitizer Designs and Their Application in Triplet–Triplet Annihilation Upconversion

New Bichromophoric Triplet Photosensitizer Designs and Their Application in Triplet–Triplet Annihilation Upconversion
Qi Chen, Yiming Liu, Xinyan Guo, Yuguo Ma, Dahui Zhao
As indispensable molecular components, photosensitizers play a crucial role in determining the quantum efficiency of triplet–triplet annihilation upconversion (TTA UC). This emergent technology has attracted great attention in recent years for realizing large anti-Stokes shifts with noncoherent excitation sources. In a typical TTA UC, low-energy photons are first harvested by the photosensitizers, which upon intersystem crossing (ISC) undergo triplet–triplet energy transfer (TTET) to emitters (i.e., annihilators). Following the bimolecular TTA among the emitters, high-energy photons are given off by the singlet excited state of the emitters. Apparently, the efficiencies of photon absorption, ISC, and TTET are all dependent on the sensitizers. With a Dexter-type ET mechanism requiring collisional interactions, a long triplet lifetime of the energy donor (photosensitizer) is evidently favorable for enhancing the efficiency of TTET. This progress report summarizes the recent developments of photosensitizers used for TTA UC, many of which feature a bichromophoric molecular scaffold. Among the various consequences and functions entailed by such bichromophoric designs, the extended triplet lifetime is a particularly advantageous property for TTA UC. Additionally, these new potent photosensitizers with long triplet lifetimes are also useful for other applications such as singlet oxygen sensitization and oxygen sensing. Molecular design principles of photosensitizers applicable to triplet–triplet annihilation upconversion (TTA UC) are discussed. Bichromophoric molecular scaffolds have been widely adopted recently. In addition to enhancing light harvesting, the bichromophoric designs are effective at extending triplet lifetime of the system. Such a unique property ensures efficient energy transfer from sensitizer to annihilator and promotes efficient TTA UC.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adom.201700981

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.