General R-matrix approach for integrating the multiband image equation in layered semiconductor structures Original Research Article

A Fortran 90 code is provided for calculating the electron reflection and transmission coefficients in semiconductor heterostructures within the 14-band image approximation. The code may easily be adapted for use with any image model, including magnetic field and/or strain effects, for example. Numerical instability, which is problematic in type-II systems due to the simultaneous presence of propagating and evanescent states, is reduced by developing a novel log-derivative R-matrix approach based on the Jost solution to the image equation.