Theory of conduction in polysilicon: Drift-diffusion approach in crystalline-amorphous-crystalline semiconductor system—Part II: General I-V theory

A general model for conduction in polysilicon is presented for arbitrary applied voltage. The model incorporates the effect of mobile carrier redistribution under bias and accounts for the high field switching in amorphous grain boundary. Microscopic mobilities used for describing the carrier transport provides a physical basis for introducing the grain voltage across the unit cell of polysilicon. The voltage, in turn, distributes itself to preserve a constant current density therein. This new criterion yields a new voltage partitioning scheme, and a general expression for the corresponding current is derived in terms of pertinent system parameters.