Organic light-emitting diodes (OLEDs) have attracted considerable research attention due to their applications in flat-panel displays and solid-state lighting.[1, 2] Phosphorescent OLEDs (or PhOLEDs) employing late transition metal complexes as emitters are particularly attractive due to their ability to harvest both singlet and triplet excitons, making it possible to achieve internal quantum efficiencies of 100%.[1, 2] However, due to the long excited- ...
