Analytical model of drift and diffusion of charge carriers in organic light-emitting diodes in the presence of a space charge

A relatively simple analytical model taking into account energy disorder and space charge effects is proposed for calculating the current-voltage characteristics for the monopolar regime of charge transfer in thin layers of disordered organic materials. The dependence of the minimal energy barrier height for injection, for which the space charge effects can be disregarded, is determined as a function of the layer thickness and the Gaussian energy distribution width.