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

We report the compensation of interfacial states formed by interfacial misfit dislocation (IMF) arrays via delta-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 (I-RB) was observed in the heterogeneous GaSb/GaAs IMF sample (73 mu A at -5 V) compared to the homogeneous GaAs control sample (3.9 mu A), which does not contain IMF. This increase in I-RB is attributed to the interfacial states. Hence, the interfacial states are compensated by delta-doping the GaSb/GaAs interface using Te atoms. A low turn-on voltage of 0.85 V and a very low I-RB of 0.1 nA were achieved for the delta-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.