High-performance InGaP/GaAs superlattice–emitter bipolar transistor with multiple S-shaped negative-differential-resistance switches under inverted operation mode

Based on the employments of an InGaP/GaAs superlattice emitter and a thin InGaAs pseudomorphic base structure, the device with excellent transistor action and multiple S-shaped negative-differential-resistance (NDR) switching behavior are achieved. Under normal transistor operation mode, the tunneling electrons could easily transport from InGaP/GaAs superlattice over the n-GaAs emitter layer into the thin InGaAs pseudomorphic base region for reducing the base–emitter turn-on voltage and promoting the current gain. In particular, an interesting multiple S-shaped NDR behavior is observed under inverted operation mode due to the avalanche multiplication and confinement effect for electrons at the interface between superlattice and emitter layer, respectively. As an appropriate voltage source and a load resistor are applied, three stable operation points are obtained.