Conduction in polycrystalline silicon: Diffusion theory and extended state mobility model

We present a new model for conduction in polycrystalline silicon based on an extended state mobility in the disordered grain boundary and the diffusion theory of current. This analysis for the first time satisfactorily explains-without the use of scaling or artificial factors-experimental data on current density, mobility, resistivity, and the activation energy for carriers in polysilicon. An attractive feature of this theory is that it provides simple expressions for J, µ, and ρ which may even be derived from an equivalent circuit model. Also, these expressions reduce, within appropriate limits, to the corresponding terms for single crystal or amorphous material.