Physics-Based Determination of Carrier Effective Mass Assumed in Density Gradient Model

Abstract

In this paper, we describe the physics-based determination of the carrier effective mass assumed in a density gradient model (DGM). We show that the effective mass assumed in a conventional DGM corresponds to that along the quantization direction assumed in the Schrödinger–Poisson (SP) solver, and that the DGM produces a good quantum correction for a system with a smooth conduction band bottom profile. Assuming an abrupt jump in the conduction band bottom profile of a heterostructure system, the physics-based determination of parameters is required to obtain agreement with the SP solver result. Whether the physical meaning of the effective mass holds is examined for the two-fluid description of the DGM.