Affiliation:
1. Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, Nankai University 1 , Tianjin 300071, China
2. Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School 2 , Worcester, Massachusetts 01605, USA
Abstract
Triplet–triplet annihilation upconversion (TTA-UC) has made major advances in many emerging fields in recent years, such as solar light harvesting, photocatalysis, biological imaging, and sensing. TTA-UC consists of photosensitizers and annihilators. In addition to acting as emitters, chemical modification of annihilators has expanded their roles to include the formation of organic gel to avoid oxygen-mediated triplet quenching, amplifying the asymmetry factor of circularly polarized luminescence, constructing an upconversion sensor as recognition units, serving as photoremovable protecting groups, and photocatalysts to realize long-wavelength light-driven organic transformations. Here, we will focus on the significant applications of functionalized annihilators other than photoluminescence, which are manifested via chemical modification with other functional units. Finally, we will elaborate on the existent issues with TTA-UC, including challenges in molecular design, material development, and emerging field applications. In accordance with our research experience, we will propose potential solutions.