Fig. 1: Qualitative energy diagram for the heteroleptic Ir(III)-dopants.
From: Ancillary ligand increases the efficiency of heteroleptic Ir-based triplet emitters in OLED devices
The excitation of heteroleptic Ir-dopants (S0) affords to the singlet excited state (S1) which further undergoes the intersystem crossing to the triplet state (T1). This T1 state either emits light by phosphorescence (kr) or is excited to the T2 state that is responsible for the non-radiative decay (knr).
