Study of the Deep Levels of a GaAs/p-GaAs1−xBix Heterostructure Grown by Molecular Beam Epitaxy

Deep-level densities of p-GaAs1−xBix and at the GaAs/p-GaAs1−xBix heterointerface have been shown to be sufficiently low for device applications based on the results of deep-level transient spectroscopy, isothermal capacitance transient spectroscopy and admittance spectroscopy. Although the metastable alloy of GaAs1−xBix is grown by molecular beam epitaxy at low temperature (370 °C), the deep-level density of p-GaAs1−xBix is suppressed such that it is on the order of 1015 cm−3. The state density at the heterointerface was determined to be 8 · 1011 cm−2eV−1, which is comparable to other III–V heterointerfaces formed at high temperatures. The surfactant-like effect of Bi is believed to prevent defect formation during low-temperature growth.