Grain boundary barrier height in base and space charge regions

Abstract

The influence of grain boundary barrier height is of great importance for polycrystalline electronic devices and solar cells. The g.b. barrier height is computed in a forward biased one-sided step junction. Within the base, it is calculated by means of analytical expressions which depend on the interface state distribution. Within the space charge region, the population of the interface states is considerably changed on taking the band bending into account. In this region, the g.b. barrier height is obtained by means of a numerical solution of the two-dimensional Poisson's equation. The energy band diagram of the junction in the vicinity of the boundary is given. The variation of the g.b. barrier height as a function of the distance from the junction has been determined for monoenergetic and uniform interface state distributions and for different direct bias voltages.