Time of flight transients analysis in photo-excited molecular doped polymers

Charge transport in molecular doped polymers (MDP) is analyzed by a new formalism taking into account spatial dispersion effects also. Charge packets are injected in thin films of photoreceptor materials by pulsed UV photo-excitation to perform time of flight (TOF) experiments. The transient currents are related in this work to thermal and electric field excitation mechanisms using new dispersion parameters. The parameters used for describing the charge spatial dispersion are the velocity distribution within the moving charge packet and the trapping time. The formalism uses the classical electrodynamic equations with proper limiting conditions. This work analyzes the experimental transients using the equation of current displacement, and a simple deep trapping model. The results are different from those obtained for semiconductors.