Patent ID: 7635879

Claim:
An electronic device comprising a semiconductor substrate, wherein said semiconductor substrate is selected from the group consisting of GaSb, GaAs, and InP, an undoped buffer layer deposited on said substrate, a sub-collector layer deposited on said buffer layer wherein said sub-collector layer is selected from the group consisting of InAlAsSb, InAlPSb, InAsSb and InGaSb, a collector layer deposited on said sub-collector layer wherein said collector layer is selected from the group consisting of InAlAsSb, InAlPSb and InGaSb, an InGaSb base layer deposited on said collector layer, an emitter layer of antimony-based material deposited on said base layer, and a highly doped cap layer deposited on said emitter layer wherein said doping is on the order of about 1×10 19 /cm 3 tellurium or silicon wherein said cap layer is selected from the group consisting of InGaSb, InAs and InAsSb; wherein the InGaSb base layer band-gap is from about 0.3 to about 0.7 eV for optimum low voltage operation at emitter-base voltages from about 0.1 to about 0.5 V; wherein the lattice constant is from about 6.1 to about 6.3 Å; and wherein the InAlAsSb or InAlPSb quaternary band gap varies from about 0.15 to about 1.5 eV.