New Type Annihilator of π-Expanded Diketopyrrolopyrrole for Robust Photostable NIR-Excitable Triplet–Triplet Annihilation Upconversion

• DOI: 10.1021/acsami.3c17679
• Publication Date: 2024-02-06T10:36:55Z
• Authors: Fang Qi; Hong-Juan Feng; Yi Peng; Lin-Han Jiang; Le Zeng; Ling Huang
• Keywords: Annihilation; Photon Upconversion; Annihilator

Near-infrared light excitable triplet-triplet annihilation upconversion (NIR TTA-UC) materials have attracted interest in a variety of emerging applications such as photoredox catalysis, optogenetics, and stereoscopic 3D printing. Currently, the practical application NIR TTA-UC requires substantial improvement photostability. Here, we found that new annihilator π-expanded diketopyrrolopyrrole (π-DPP) cannot activate oxygen to generate superoxide anion via photoinduced electron transfer, its electron-deficient characteristics prevent singlet oxygen-mediated [2 + 2] cycloaddition reaction; thus, π-DPP exhibited superior resistance photobleaching. In conjunction with photosensitizer PdTNP, efficiency is high 8.9%, which eight times previously reported PdPc/Furan-DPP. Importantly, after polystyrene film encapsulation, less than 10% photobleaching was observed for this PdTNP/π-DPP-based material four hours intensive exposure. These findings provide type extraordinary photostability, facilitating development photonics.