transient trap-limited field dependence charge carrier transport in organic semiconductors for time of flight configuration

Organic semiconducting polymers are for use in low cost electronics and photovoltaic application has technological and scientific interest in organic materials. in this paper we use the time of flight of a charge packet injected by a voltage pulse to calculate the drift velocity and mobility of holes. this technique is based on the application of a voltage applied at the anode and calculating the delay time in the appearance of the injected carriers at the other contact. this method is a simple way to determine the charge transport properties of the organic semiconductors .the effect of charge trapping mechanism on the carrier mobility in the organic layers are investigated and we discussed the theory of a electronic method to obtain the drift mobility of holes in an organic layer. finally time of flight calculations were done on organic layers and it was observed that the mobility reduces at low electric field.