Charge carrier transport in diluted hopping systems

A simple model of weak-field equilibrium carrier drift and diffusion is proposed for diluted hopping systems. The model is based on the two-site approximation accounting for positional and energetic correlations of two nearest hopping neighbors only. It is shown that energetic distribution of hopping neighbors parallels the DOS function g(E) as it does in the opposite case of systems with high concentration of hopping states. This similarity leads to similar activation energies of the mobility and diffusivity for both diluted and condensed systems