CLAIMS 1. A computer implemented method of performing transport simulation of a d is ordered semiconductor device, the method comprising: (a) receiving an input specification of composition and geometry of the disor dered semiconductor device; (b) performing a three-dimensional master equation simulation of electron and hole transport and recombination based on the input specification; (c) wherein charge transport is modeled as incoherent hopping between local ized molecular states; (d) wherein recombination is modeled as a nearest-neighbor process where an electron at a first location and a hole at a second location can recombine at either the first location or the second location, (e) wherein the first location and the second location are nearest neighbors in a set of the localized molecular states; (f) wherein a rate of the recombination is modeled as a product of a prefactor , hopping rates and state occupancies; (g) wherein the prefactor is given by an empirically derived analytic expres sion; and (h) providing simulated transport results of the disordered semiconductor d e vice as an output. 2. The method of claim 1, wherein e is electron charge, wherein o is the dielectric permittivity of free space, wherein e$_{r}$ is the relative dielectric permittivity of the organic semiconductor, wherein a is a lattice constant of the disordered semi conductor, wherein A $_{¾}$i Boltzmann’sconstant, wherein T is temperature, and wherein is an energy width of a Gaussian density of states of the disordered semiconductor; and wherein the empirically derived analytic expression is given by