Simulation of emitter size effects in the coupled-quantum-well base resonant tunneling transistor

A resonant tunneling transistor, which has a base in the well region of a coupled-quantum-well structure, was studied using a quantum distributed model. By investigating the relationship between the disappearance of the negative differential resistance and emitter size, a large potential drop near the base electrode was found to be crucial in the disappearance of the negative differential resistance, which causes localization in the collector current. It was shown that the negative characteristics disappear, when the potential drop in the well region parallel to the interface is as large as the difference of first and second resonant energy of electron.