Modeling the Electrical Stabilities of Organic Light‐Emitting Diodes

The ratio ( R ) of the molecular density of emissive layer to the carrier density in exciton formation zone has been provided to weigh the electrical stability of organic light‐emitting diode and simulated via the general mode of carrier device lifetimes. With current density increasing from 1 to 500 mA cm −2 , the molecular density of emissive layer enabling the largest R , that is, the best electrical stability of device, gradually increases from 7.5 × 10 19 to 1.5 × 10 21 cm −3 . At a given current density, R increases with the average bandgap of emissive layer increasing. There is a power law dependence of R on current density. For host–guest emissive layer, the electrical stability of device decreases with guest concentration increasing, mostly because the average bandgap of the host–guest emissive layer decreases. The current research provides some deep insights into developing the emissive layers of organic light‐emitting diodes toward high luminance applications.