Numerical impedance model of single‐layer organic light‐emitting diodes with uniformly distributed recombination

The impedance model is of great importance for analyzing the transport properties of organic light-emitting diodes (OLEDs). We report on the numerical impedance model for bipolar drift transport in single-layer OLEDs under the assumption of uniformly distributed recombination-rate density in the recombination region. With the help of this model, a concise empirical formula is obtained from which the sum of electron mobility and hole mobility can be determined from the characteristic frequency of the negative differential susceptance and the capacitance at the low-frequency limit. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim