Investigation into the modeling of field-effect mobility in disordered organic semiconductors

Organic semiconductors have attracted significant interest because of their potential application in electronic devices. One of the most important parameters in such an application is the carrier mobility, which is low when compared with the inorganic semiconductors. In the past, significant effort has been spent to produce high mobility organic semiconductors, even though the best room temperature value reported is only a few cm²/V.s. In this work, we examined the field-effect carrier mobility in pentacene by correlating reported data on polycrystalline samples with simulations based on the correlated disorder model (CDM). Using the rms width of the density of states (DOS) as the variable, we were able to produce a good match. Our results suggested that the carrier mobility in polycrystalline pentacene might be primarily dependent on σ, the rms width of the DOS. Furthermore, a parameter extraction scheme was proposed and applied to pentacene data reported in the literature.