A Gummel-Poon model for single and double heterojunction bipolar transistors

An analytical model for single- and double-heterojunction bipolar transistors developed by using the concepts of the Gummel-Poon model is discussed. The equations for injected minority carrier concentrations are developed using thermionic diffusion theory. Linking current and total charges in the base are calculated. The early voltages are treated as a function of the applied voltage rather than as a constant. The tunneling effect is considered for abrupt heterojunctions. The resemblance of this model to the SPICE bipolar junctions transistor (BJT) model makes it easy to implement in SPICE.<
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