Transition from dispersive to non-dispersive hole transport in poly-N-vinylcarbazole/polycarbonate mixtures

Isothermal time-of-flight (TOF) measurements carried out on films of a poly(N-vinyl carbazole)/polycarbonate mixture in the temperature range 220 to 370 K show that with increasing temperature a transition from dispersive (250 K) hole transport occurs. A comparison of thermally stimulated currents, thermoluminescence, isothermal TOF, and thermally stimulated TOF measurements indicates that the low-temperature dispersive transport results from frozen-in energetic disorder rather than from multiple trapping.<>