Temperature and field dependence of the charge injection from metal electrodes into random organic media

Due to the Gaussian disorder of the molecular levels of the classical thermal activated injection mechanism, it is shown that the injection current from a metal to a disordered dielectric obeys the law ln(j)∝√E. The injection efficiency increases with increasing disorder because of the formation of the rare fluctuational pathways. The carrier transport occurs mostly along these pathways at sufficiently high voltages, corresponding to the performance of organic devices.