Chirped superlattice hot electron transistor

We report a novel bandgap-engineered DHBT that (i) eliminates the current-blocking potential barrier between the base and the collector, and (ii) injects hot electrons into the collector at room temperature. Using a Ga/sub 0.47/In/sub 0.53/As/Al/sub 0.49/In/sub 0.51/As DHBT with a composite collector consisting of a 50 nm short-period chirped superlattice (CSL) and a 350 nm Ga/sub 0.47/In/sub 0.53/As collector we demonstrate that the energy band profile and the electrostatic potential arising from the ionized dopants in the base-collector space charge region can be properly tailored to produce a barrier-free conduction band for electrons, similar to that of a homojunction.