Modeling of bistable device I-V characteristic resulting from conductivity modulation in semiconductors

The bistable I-V characteristic in a silicon diode-like device structure that resembles the double-base diode is predicted by numerical solution. This bistable characteristic results from the conductivity modulation effect coupled with an ohmic voltage drop produced by the current through a shunt resistor. The back-surface field effect has a significant influence on the minority-carrier transport of this type of bistable I-V characteristic. A two-dimensional numerical simulation is performed to explore the steady-state bistable I-V characteristic including a negative dynamic conductance region. To better understand this mechanism, a DC equivalent circuit based on a one-dimensional current-flow model is proposed. The I-V characteristic obtained by this equivalent circuit agrees well with an exact two-dimensional numerical simulation result