Nondispersive hole transport in a polyfluorene copolymer with a mobility of 0.01 cm2 V-1 s-1

The hole mobility in the fluorene copolymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4(')-(N-(4-sec-butylphenyl)) diphenylamine)] (TFB) was measured using the time-of-flight technique. Transport was found to be nondispersive throughout the temperature range between 220 and 350 K, indicating the absence of intrinsic traps in this material. At room temperature, TFB shows a hole mobility of 0.01 cm(2) V-1 s(-1), with a weak field dependence. The hole mobility is independent of sample thickness in the range between 0.9 and 6.4 mu m. These results are in agreement with a narrow transport manifold, with a width of 65.9 +/- 0.5 meV. (c) 2006 American Institute of Physics.