Efficient thermally-activated delayed fluorescence in endohedral metallofullerenes

• Applicant: Dr. Alexey A. Popov
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 421793592

The recent discovery of efficient thermally activated delayed fluorescence (TADF) in the endohedral metallofullerene (EMF) Y3N@C80 indicates that EMFs can be strongly luminescent materials. However, the photophysical properties and the electron distribution in their excited states are not well understood. In this project a systematic study of the luminescent properties of a series of EMFs and their derivatives will be performed. Variable-temperature steady-state and time-resolved luminescence measurements will reveal other EMFs showing efficient TADF. The influence of chemical derivatization on the TADF will be studied for fullerene cyclo- and radical adducts with different addition patterns. Conventional and optically-detected electron spin resonance spectroscopy will be used to study the spin density distribution in the photoexcited triplet states of EMFs. Time-dependent DFT calculations will be performed to predict energetics and spatial distribution of electron excitations in EMFs and rationalize experimental observations. This work will disclose the factors affecting the mechanism of the radiative and non-radiative decay of the photoexcited states and efficiency of the luminescence of EMFs and establish their potentials as emitters in the red to NIR range, as thermal sensors, or as singlet oxygen sensitizers.

• DFG Programme: Research Grants