Energetic disorder, spatial correlations, and the high-field mobility of injected charge carriers in organic solids

In a large class of disordered organic solids, the observed field and tempe rature dependence of the mobility of photoinjected charge carriers arises f rom specific statistical features of the disordered potential energy landsc ape through which they move. In materials with polar constituents, energy f luctuations exhibit strong spatial correlations, with deep energetic valley s developing only over large length scales. We present a scaling analysis t hat shows how the hierarchical field-induced Rattening of fluctuations of d ifferent magnitudes gives rise to field dependent (e.g., Poole-Frenkel type ) mobilities characteristic of the spatial correlations from which they ari se.