Ir(III) complexes are often used as triplet emitter dopants in phosphorescent organic light-emitting diodes (PhOLEDs). Optimizing their photoluminescence quantum yields (PLQY) at room temperature and controlling the light-outcoupling is key to attain highly performant PhOLEDs.[1] This work demonstrates that the quantum chemical modelling of phosphors is a helpful tool to: i) attain quantitative predictions of their PLQY and ii) rationalize the amount of light-outcoupling. More in details, we show that the quantitative prediction of the PLQY of blue-to-green Ir(III) complexes can be derived exclusively from electronic structure calculations and the use of simplified kinetic models.[2] Within these models, only a few calculations are needed: computing the radiative rate from the emissive state and characterizing the potential energy surfaces of the temperature-dependent non-radiative deactivation channels. This approach is extremely beneficial for the in silico prescreening of promising deep blue PhOLED emissive materials. Finally, the accurate calculation of the singlet-triplet transition dipole moments provides important insights into the design of Ir(III) complexes with improved outcoupling factors.
[1] Computational insights into the photodeactivation dynamics of phosphors for OLEDs: a perspective. D. Escudero and D. Jacquemin, Dalton Trans., 2015, 44, 8346.
[2] Quantitative prediction of photoluminescence quantum yields of phosphors from first principles. D. Escudero, Chem. Sci., 2016, 7, 1262.
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