Fig. 1: Schematic illustrations of narrowband deep blue organic afterglow through short-range charge transfer (SRCT).
From: Short-range charge transfer for efficient ultra-narrowband deep blue afterglow
a Schematic illustration of the HOMO–LUMO distribution on typical donor–acceptor and MR-type chromophores. b Photophysical processes of room-temperature phosphorescence (RTP) and SRCT-induced thermally activated delayed fluorescence (TADF) afterglow. HOMO and LUMO are the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals, respectively. S0, S1, and T1 represent the ground state, the lowest singlet excited state, and the lowest triplet excited state, respectively; v refers to the vibration energy levels; ISC, Exc. Phos. and non-rad. refer to intersystem crossing, ultraviolet (UV) light excitation, phosphorescence and non-radiative decay, respectively. kp, kRISC, kDF, and knr represent rate constants of phosphorescence, reverse intersystem crossing, delayed fluorescence and non-radiative decay, respectively. kB and T are the Boltzmann constant and temperature, respectively. c Chemical structures of the corresponding narrowband deep blue chromophores.
