Thermally Activated Delayed Fluorescence in Fullerenes

Abstract

This report reviews the thermally activated delayed fluorescence (TADF) displayed by fullerenes. From the analysis of the steady-state data, time-resolved data, or by a combination of both, it is possible to determine several important photophysical parameters of fullerenes. Herein we also cover the development of temperature and oxygen sensors based on the TADF effect exhibited by fullerene C 70 . Despite the work already carried out, knowledge of the photophysics of fullerenes and derivatives is still incomplete, and much remains to be done in this area and in the improvement of sensor systems based on fullerenes.

Fluorescence of fullerene C70 in ionic liquids

“…Oxygen, together with nitrogen, presents the lowest values for the above parameters. These findings lead us to investigate the possible use of ILs as media for oxygen and temperature sensors based on the thermally activated delayed fluorescence (TADF) of C 70 [31], as TADF is only detected in the presence of residual amounts of oxygen, owing to the efficient quenching of the triplet state by oxygen. A solution of C 70 in [THTDP][Tf 2 N] was degassed and sealed afterwards.…”

Thermally Activated Delayed Fluorescence Materials Towards the Breakthrough of Organoelectronics

“…Fullerenes (C 60 , C 70 , and higher fullerenes), which possess three‐dimensional carbon structures that can be viewed either as large carbon molecules or as tiny nanoparticles with well‐defined composition and shape, have been widely used as promising component for organoelectronics especially for OPVs, since their discovery in 1985 . The unique photophysical and photochemical properties arising from many delocalized π electrons and the high symmetry and curvature of the structure, are marked with a series of characteristic features such as small Δ E ST (0.30 eV for C 70 ), long intrinsic phosphorescence lifetime (28 ms for C 70 ), and the high ratio of the reverse intersystem crossing (RISC) that is very close to 100% . These features make fullerenes good candidates for TADF materials .…”

“…The major applications based on the TADF properties of fullerences were limited to temperature and oxygen sensors when dispersed in a polymer matrix. Previously, the progress and the development of fullerenes with TADF properties have been reviewed in 2008 . We will focus on the work afterward.…”

Recent Developments in the Thermally Activated Delayed Fluorescence of Fullerenes

“…For a given fluorophore, TADF is usually much weaker than its PF. Although known for many years, TADF continues to be a relatively rare phenomenon (9).…”