Modelling of asymmetric n-p junction enriched with charge carriers in equilibrium state

Abstract

Modelling n-p-junction is an urgent task, because theoretical models do not describe all the properties of semiconductor structures with different content of impurities. The influence of impurities on the properties of asymmetric n-p-junction was analyzed in the paper. The Poisson equation in the space charge region (SCR) of the equilibrium n-p-junction was solved numerically. The charge density in the SCR was also calculated. It has been shown that the structure of SCR of strongly asymmetric n-p-junction substantially differs from the model of depleted charge carriers, and includes four parts: 1 – highly doped region, wherein the main charge carriers partially compensate the charge of the ionized impurities; 2 – low-doped region containing ionized impurities of the opposite sign with respect to the first, enriched with charge carriers, increasing the charge of ionized impurities; 3 – lowly doped region, wherein the concentrations of electrons and holes much less than the concentration of ionized impurities; 4 – lowly doped region, wherein the main charge carriers partially compensate the charge of the ionized impurities.