Calixarenes as High Temperature Matrices for Thermally Activated Delayed Fluorescence: C70 in Dihomooxacalix[4]arene

Abstract

Thermally activated delayed fluorescence (TADF) of 12C70 and 13C70 was observed up to 140 °C in a p-tert-butyldihomooxacalix[4]arene solid matrix, a temperature range significantly higher than that of previous TADF quantitative studies. An effective singlet–triplet energy gap of 29 kJ/mol and triplet formation quantum yields of 0.97 and 0.99 were measured for 12C70 and 13C70, respectively. The photophysical properties of the two fullerenes in this new matrix are comparable to those obtained in polystyrene at a lower temperature range. Calixarenes are proposed to be suitable matrices for high temperature TADF studies and applications.

Keywords

• thermally activated delayed fluorescence (TADF)
• organic light-emitting diodes (OLEDs)
• fullerene C70
• homooxacalixarenes