Thickness scaling of space‐charge‐limited currents in organic layers with field‐ or density‐dependent mobility

Abstract

Abstract An exact solution is provided for the current density‐voltage ( J – V ) characteristics of space‐charge limited transport of a single carrier in organic layers with field‐dependent mobility of the type μ ( E ) = μ 0 exp ( γ √ E . The general scaling relationship for field‐dependent mobility occurs in terms of the variables JL and V / L . For the density‐dependence of the mobility found in organic field‐effect transistor measurements, the thickness scaling occurs in terms of different variables, J 1/ β L and V / L . The proposed scaling is a useful test for distinguishing field‐ and carrier density‐dependent mobility in disordered organic semiconductors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)