Affiliation:
1. Research Center for Analytical Sciences and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Nankai University Tianjin 300071 China
2. Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
Abstract
AbstractEffective strategies to manage the triplet state of chromophores are desirable in terms of their crucial role in photonic and optoelectronic technologies. However, triplet excited‐state energy level regulation of organic molecules remains elusive. Here, non‐conjugated n–π spatial electron coupling is demonstrated within boron‐dipyrromethene (BODIPY) and can greatly reduce the low‐lying triplet state (T1) to 1.34 eV without the conventional need for π‐conjugation extension. Moreover, the close alignment between T1 states of this BODIPY derivative and the photosensitizer PtTNP contributes to the reversible triplet energy transfer, namely the intermolecular triplet excited‐state equilibrium. Furthermore, to the best of the knowledge, the first BODIPY‐based near‐infrared light‐activated triplet fusion upconversion (NIR TF‐UC) with an upconversion quantum efficiency of 13.3% is implemented. On this basis, the air‐stable solid‐state NIR TF‐UC material is successfully fabricated, whose upconverted emission can still be seen at an ultralow NIR power density of 6.4 mW cm−2. This new strategy to implement triplet state modulation will accelerate the development of NIR TF‐UC and other important areas involving triplet state, such as photoredox catalysis, photodynamic therapy, and photovoltaic devices.
Funder
Nankai University
National Key Research and Development Program of China
National Natural Science Foundation of China
Natural Science Foundation of Tianjin Municipality
Subject
Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials