The effects of electric fields and temperatures on the carrier mobilities in organic layers and at electrode/organic interfaces were investigated by using three-dimensional Monte-Carlo simulation. The mobility variations in the organic layers and at the electrode/organic layer interfaces were described on the basis of the calculated results. The density of deep sites significantly affected the difference in the mobility behavior between the organic layers and the electrode/organic interfaces. (C) 2010 Elsevier B.V. All rights reserved.