Electroluminescence of type II broken-gap p-Ga0.84In0.16As0.22Sb0.78/p-InAs heterostructures with a high-mobility electron channel at the interface.

Ga0.84In0.16As0.22Sb0.78 quaternary solid solutions, lattice matched to InAs, were grown by liquid phase epitaxy on (100)-oriented p-InAs substrates from In-rich melt. The p-type Ga0.84In0.16As0.22Sb0.78 layers were intentionally undoped or slightly doped with Sn to the hole concentration about p∼5×1016 cm-3. This allowed us to obtain a high-mobility∼(3.5-5.0)×104 cm2 V-1 s-1 electron channel at the type II broken-gap p-Ga0.84In0.16As0.22Sb0.78/p-InAs heterointerface. Low-temperature (T=5 K) electroluminescence spectra exhibited two pronounced emission bands hν1=0.372 eV and hν2=0.400 eV under forward bias. The emission band hν2 was split into two lines and was attributed to interband transitions through acceptor and valence-band states in the bulk InAs, whereas emission band hν1 was ascribed to interface-related radiative transitions of electrons from the two-dimensional electron channel to the interface states at the p-Ga0.84In0.16As0.22Sb0.78/p-InAs heteroboundary. [ABSTRACT FROM AUTHOR]