Enhancement of triplet-sensitized upconversion in rigid polymers via singlet exciton sink approach

Abstract

Quenching of emitter singlets by the sensitizer limits the efficiency of sensitized upconversion, unless an emissive exciton sink is employed.

Plug-and-Play Optical Materials from Fluorescent Dyes and Macrocycles

“…Polymers, in particular, are attractive matrices in which to incorporate optically active fluorophores on account of their ease of processability relative to molecular crystals. Thin film applications, such as, exciton upconversion, 8,18 and solid-state dye lasers, 56 typically, require high loading of dyes into polymers to generate the desired effect. However, achieving the corresponding high loading using traditional dyes can prove challenging due to the dye-dye interactions (aggregation-caused quenching) described as concentration quenching.…”

“…Fluorescence 1 is a property of matter that is critical for many technologies, such as OLEDs, 2,3 as well as new applications, such as triplet-triplet annihilation upconversion. [4][5][6][7][8] Fluorescence has been the subject of a large number of discoveries including the revolutionary lead halide perovskites 9 made by mixing and matching ionic building blocks to control optical properties. Fluorescence is also readily seen in many classes of dye molecules that display bright emission in dilute solution, which has motivated their widespread use as biolabels.…”

Potassium Poly(Heptazine Imide): Transition Metal‐Free Solid‐State Triplet Sensitizer in Cascade Energy Transfer and [3+2]‐cycloadditions

“…Ease of separation, higher thermo‐chemical stability, and possible application on large scale make solid‐state sensitizers more attractive than homogeneous analogues. π‐conjugated triplet sensitizers have been a topic of research in past decades and have been quite successfully used in areas such as light energy conversion, LEDs fabrication, photon upconversion, cells imaging . However, only few examples are known using such materials in photocatalysis .…”

Kalium‐Polyheptazinimid: Ein übergangsmetallfreier Festkörper‐Triplett‐Sensibilisator in Kaskadenenergietransfer und [3+2]‐Cycloadditionen

“…Leichte Trennbarkeit, höhere thermochemische Stabilität und mögliche Anwendung im großen Maßstab machen Festkörpersensibilisatoren attraktiver als homogene Analoga. π‐konjugierte Triplett‐Sensibilisatoren waren in den vergangenen Jahrzehnten Gegenstand der Forschung und wurden recht erfolgreich bei der Lichtenergieumwandlung eingesetzt, beispielsweise bei der Herstellung von LEDs, zur Umwandlung von Photonen bei der Hochkonversion, der Bildgebung von Zellen usw. Es sind jedoch nur wenige Beispiele für den Einsatz solcher Materialien in der Photokatalyse bekannt .…”