Bi-induced highly n -type carbon-doped InGaAsBi films grown by molecular beam epitaxy

Carbon-doped InGaAsBi films on InP/Fe (100) substrates have been grown by molecular beam epitaxy (MBE). It has been found that Bismuth incorporation induces extremely high n -type carbon-doped InGaAsBi films, and its electron concentration increases linearly up to 10 21 cm −3 (highest reported to date for n -type III-V semiconductor materials) with increased CBr 4 supply pressure, implying InGaAsBi to be a prospective ohmic contact material for InP-based terahertz transistors. It also has been proved by secondary ion mass spectroscopy that the alloy composition of carbon-doped InGaAsBi is altered by the preferential etching effect of CBr 4 , but the etching effect on the Bi content is negligible.