In silico material discovery for highly efficient OLEDs and multiscale charge transport simulations

Abstract

Recently, organic light-emitting diodes (OLEDs) exploiting thermally activated delayed fluorescence (TADF) have made remarkable progress. In principle, TADF materials can convert all electrogenerated singlet and triplet excitons into photons, enhancing OLED efficiency dramatically. Through a simple high-throughput screening method based on theoretical computations and simple experiments, we discovered highly-efficient TADF materials for vacuum-deposited, solution-processed, and solution-processed host-free OLEDs. These devices achieved external quantum efficiencies of 29.6%, 18.6%, and 17.6%, respectively, without using any out-coupling treatments. Our recent multiscale charge transport simulations in amorphous organic thin layers are also shown. On the basis of the combined use of quantum chemical calculations, molecular dynamics, and kinetic Monte Carlo simulations, experimental charge mobilities are well reproduced without using any adjustable parameters.