Revealing the influence of steric bulk on the triplet–triplet annihilation upconversion performance of conjugated polymers

• Published in: Scientific reports Vol. 11; no. 1; p. 19585
• Main Authors: O’shea, Riley, Kendrick, William J., Gao, Can, Owyong, Tze Cin, White, Jonathan M., Ghiggino, Kenneth P., Wong, Wallace W. H.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.10.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/298/398; 639/638/439/943; 639/638/440/948; 639/638/455/954; Copolymers; Efficiency; Energy transfer; Humanities and Social Sciences; Laboratories; Monomers; multidisciplinary; Nitrogen; Palladium; Phosphorescence; Photochemicals; Photons; Polymers; Science; Science (multidisciplinary); Solvents
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-99179-y

A series of poly(phenylene-vinylene)-based copolymers are synthesized using the Gilch method incorporating monomers with sterically bulky sidechains. The photochemical upconversion performance of these polymers as emitters are investigated using a palladium tetraphenyltetrabenzoporphyrin triplet sensitizer and MEH-PPV as reference. Increased incorporation of sterically bulky monomers leads to a reduction in the upconversion efficiency despite improved photoluminescence quantum yield. A phosphorescence quenching study indicates issues with the energy transfer process between the triplet sensitizer and the copolymers. The best performance with 0.18% upconversion quantum yield is obtained for the copolymer containing 10% monomer with bulky sidechains.