Field-dependent thermal injection into a disordered molecular insulator

A Monte Carlo simulation is performed of emission-limited injection into an energetically disordered molecular insulator. For thermal injection, disorder leads to the increased probability for injected carriers to return to the electrode. As a result, enhanced non-linearity of the injected current is found with respect to applied electric field compared to that caused by the image force only. Particularly, the field-dependent part of the effective activation energy is significantly increased by disorder. These effects are in sharp contrast to those found for hot injected carriers.