Application of the Fragment Molecular Orbital Method to Organic Charge Transport Materials in Xerography: A Feasibility Study and a Charge Mobility Analysis

The charge transport rate constant is calculated using the Marcus theory for a pair of fragments in two different ways: neglecting and accounting for the effect of the environment. The latter is accomplished with the fragment molecular orbital (FMO) method. In order to apply FMO to charge transport materials (CTMs), it is first validated by comparing the accuracy and timings to full calculations without fragmentation, for several types of fragmentation models applied to dispersive and cross-linked CTMs. Secondly, the Marcus theory combined with FMO is applied to simulate charge transport phenomena using Einstein's diffusion model or kinetic Monte Carlo (KMC) method. The result of charge mobility simulation shows qualitative agreement with experiment, and KMC is found to give better results than the diffusion theory because it takes into account the directionality and the charge transport path.