Carbon-doped GaAs and InGaAs grown by solid source molecular beam epitaxy and effect of III/V ratio on their properties

Carbon-doped gallium arsenide (GaAs:C) and indium gallium arsenide (InGaAs:C) samples were grown by solid source molecular epitaxy using carbon tetrabromide (CBr4) as a carbon source. The samples were characterized using Hall and photoluminescence measurements. For the purpose of investigation, GaAs:C and InGaAs:C samples were grown using different arsenic to group III (V/III) ratio. This study showed that V/III ratio affects the formation of mid-gap non-radiative recombination centers in GaAs:C and InGaAs:C. It is also found that the mid-gap recombination centers were greatly suppressed when V/III ratio of 25 and 20 were used in growth of GaAs:C and InGaAs:C layers, respectively. Furthermore, GaAs:C-based and InGaAs:C-based heterojunction bipolar transistors have been grown and their DC performance characterized.