  In this article, we present an alternative method for simulating charge
transport in disordered organic materials by using a buffer lattice at the
boundary. This method does not require careful tracking of carrier's hopping
pattern across boundaries. Suitability of this method is established by
reproducing the field dependence of mobility, carrier relaxation and carrier
diffusion in disordered organic systems obtained by simulating the charge
transport for the full length of the systems along the field direction without
and boundary condition. The significance of the buffer lattice is emphasized by
simulating field dependence of mobility without using a buffer lattice, which
results in negative field dependence of mobiltiy (NFDM) at low field regime due
to the extra bias the carrier gains from the neglected hops and boundaries
along field direction.
