Structural effects on the carrier mobility of organic field-effect transistors

This work examined pentacene organic field-effect transistors built on polycrystalline, single-grain, and single-crystal thin films. Mobility data obtained in the literature were matched to equations developed from charge hopping and the Gaussian disordered model. Our results indicated that it was possible to harmonize conventional dispersive charge transport with the hopping process. Assuming that charge conduction between trap states in the inter-granular region was barrier-height limited and affected by the gate voltage, we were able to estimate the material parameters appearing in our model equations. Our results indicated that very different values of the rms widths of the density of (transport) states existed in the different thin films.