Increased vis-to-UV upconversion performance by energy level matching between a TADF donor and high triplet energy acceptors

摘要

A question at issue in triplet-triplet annihilation-based photon upconversion (TTA-UC) has been how to maximize the anti-Stokes shift, which requires minimization of the energy losses in intersystem crossing (ISC) of donors and consequent energy transfer (TTET) to acceptors. This is resolved by the energy level matching between a thermally activated delayed fluorescence (TADF) sensitizer and emitters with the highest triplet and singlet energy levels.