Compensation of interfacial states located inside the “buffer-free” GaSb/GaAs (001) heterojunction via δ-doping

Abstract

We report the compensation of interfacial states formed by interfacial misfit dislocation (IMF) arrays via δ-doping. The IMF arrays are located inside the “buffer-free” heterojunction of GaSb/GaAs (001). The interfacial states are measured using surface photovoltage measurements and are positioned at 0.41, 0.49, and 0.61 eV. A higher reverse bias leakage current (IRB) was observed in the heterogeneous GaSb/GaAs IMF sample (73 μA at −5 V) compared to the homogeneous GaAs control sample (3.9 μA), which does not contain IMF. This increase in IRB is attributed to the interfacial states. Hence, the interfacial states are compensated by δ-doping the GaSb/GaAs interface using Te atoms. A low turn-on voltage of 0.85 V and a very low IRB of 0.1 nA were achieved for the δ-doped sample compared to the control and IMF samples. Hence, for optoelectronic applications, such as lasers, solar cells, and detectors, this compensated IMF technology is useful for integration of buffer-free III-Sb devices on an inexpensive GaAs platform.