Abstract
Horizontal devices with photolithographically defined electrodes on glass are used in the research to measure the hole mobility in conjugated polymer. We fit the measured result with space charge limited current model. It is found that for a fixed electric field the horizontal mobility is about three orders of magnitude larger than the vertical mobility. The horizontal mobility increases with the aging of the conjugated polymer solution. High temperature treatment accelerates aging. Photo- luminescence study reveals that enhancement in horizontal mobility is a result of the alignment of aggregates by the centrifugal force of the spin. Our results may be useful to improve the polymer thin film transistor.