Monte Carlo simulation of charge transport in disordered organic systems using buffer lattice at boundary

TL;DR

This paper introduces a buffer lattice method for simulating charge transport in disordered organic materials, simplifying boundary handling and accurately reproducing key transport properties compared to traditional full-length simulations.

Contribution

The novel buffer lattice approach eliminates the need for detailed boundary tracking, improving simulation efficiency and accuracy in modeling charge transport in disordered organic systems.

Findings

Buffer lattice method accurately reproduces mobility, relaxation, and diffusion.

Without buffer lattice, negative field dependence of mobility appears at low fields.

Buffer lattice prevents artifacts caused by boundary effects in simulations.

Abstract

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.