Interface photoluminescence in type II broken-gap P–Ga0.84In0.16As0.22Sb0.78/p-InAs single heterostructures

Abstract

Mid-infrared photoluminescence has been observed from interface transitions in high quality, abrupt P–Ga0.84In0.16As0.22Sb0.78/p-InAs heterojunctions grown by liquid phase epitaxy from an In-rich melt. The Ga0.84In0.16As0.22Sb0.78 quaternary epitaxial layer was unintentionally doped and grown lattice matched on to a (100) oriented p-type InAs substrate, resulting in a P–p isotype heterojunction. The photoluminescence emission spectra were investigated and exhibited three pronounced emission bands in the spectral region from 0.30 to 0.68 eV; hν1=0.317 eV, hν2=0.380 eV, and hνL=0.622 eV. The emission band hν1 was identified with radiative transitions between electron and hole quantum well subbands in the semimetal channel at the P–GaIn0.03As0.10Sb/p-InAs interface, while the hν2 band originates from radiative transitions involving deep acceptor states in the InAs substrate. The high-energy recombination hνL is characteristic of the Ga0.84In0.16As0.22Sb0.78 bulk quaternary layer.