Electronic characteristics of the interfacial states embedded in "buffer-free" GaSb/GaAs (001) heterojunctions

We report a comprehensive study of the electronic properties and compensation of the interfacial states embedded in a majority carrier electron region either on one or both sides of the "buffer-free" GaSb/GaAs (001) heterointerface. An abrupt change observed in the forward-bias current (58 mA) for a small variation in the applied bias (0.05 V) is ascribed to the compensation of the interfacial states due to electron tunneling from GaAs into GaSb. As a result, after the first sweep, the compensated interfacial states exhibit low turn-on voltage (0.35 V) and low reverse-bias currents (30 mu A at -5 V). Similar compensation is also obtained via delta-doping or annealing the diodes. The diodes analyzed in this study are useful as the heterointerface is embedded in the majority electron region resembles with that of the n-cladding region of p-i-n structures such as lasers, detectors, and solar cells.