Consistent time-of-flight mobility measurements and polymer light-emitting diode current-voltage characteristics

We present time-of-flight mobility measurements and measured and calculated current-voltage (I-V) characteristics of structures fabricated using a soluble poly(p-phenylene vinylene) derivative. Time-of-flight measurements were used to determine the electric field dependent hole mobility. This mobility was then used, without adjustable parameters, to calculate the I-V characteristics of space-charge-limited, hole only devices. The measured and calculated I-V characteristics are in good agreement over five orders of magnitude in current. These results demonstrate that an electric field dependent mobility, without invoking trapping effects, provides an accurate description of hole transport in this polymer. (C) 1999 American Institute of Physics. [S0003-6951(99)00419-2].