A Quantum-Switched Heterojunction Bipolar Transistor.

We propose and demonstrate a totally new negative differential resistance transistor -- the quantum-switched heterojunction bipolar transistor (QSHBT). It has the highest current peak- to-valley ratio ever reported at room temperature (15 in InGaAs/InP QSHBT). More importantly, for the first time, the switching and peak-to-valley ratio can be controlled by base current injected electronically or optically. For example, a peak current as high as 72 mA or 2.9 kA/ cm sup 2 can be controlled by either a few muA's of base current or a few microwatt's of optical signal. A gain of peak current of 8650 at room temperature is obtained. The present device is grown by chemical beam epitaxy.