Multiple negative transconductance and differential conductance in a bipolar transistor by sequential quenching of resonant tunneling

Abstract

The operation of the first multistate bipolar transistor is reported. Multiple peaks are obtained in the collector current-voltage characteristics by sequentially quenching resonant tunneling through a series of double barriers placed in the emitter. GaInAs npn devices with two AlInAs/GaInAs double barriers exhibit two peaks in the direct and transfer characteristics, with peak-to-valley ratios in the latter as high as 4:1 and 20:1 at 300 and 77 K, respectively. The intrinsically multistate operation of this new transistor opens up exciting opportunities for digital and analog circuits with greatly reduced complexity and multiple valued logic.