An Integral Gummel Relation for Single and Double Heterojunction Graded-Base HBTs

Abstract

An integral Gummel charge‐control relation for both linearly graded and non‐graded base and for single or double heterojunction bipolar transistors is derived. In addition to modeling the collector current density for different heterojunction systems, the analytical model is useful for analyzing the collector offset voltage of the heterojunction bipolar transistor with or without graded energy gap in the base. Comparisons with numerical and experimental data show excellent agreement.