An improved expression of charge-carrier mobilities for disordered organic semiconductors

Many studies conducted in recent years on the mobility of disordered organic semiconductors have demonstrated that the mobility functional based on the Gaussian disorder model given by Pasveer et al. still has several shortcomings. In this paper, we present an improved expression of charge-carrier mobility, and make a comparison between some results obtained from our model and the results reported by Pasveer et al. It is shown that our improved expression can extend the results of the description of the mobility to high densities and high electric fields. The improved model can accurately reproduce the experimental current-voltage characteristics of organic electronic device based on PDPP5T:PC61BM blend. Furthermore, it is demonstrated that the effective mobility in PDPP5T:PC61BM blend gradually increases with increasing temperature, and the maximum value of the carrier density and the minimum value of the electric field appear at the interface of PDPP5T:PC61BM hole-only device.