Interface photoluminescence in type II broken-gap P–Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78]/p-InAs single heterostructures.

Mid-infrared photoluminescence has been observed from interface transitions in high quality, abrupt P–Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78]/p-InAs heterojunctions grown by liquid phase epitaxy from an In-rich melt. The Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78] 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; hν[sub 1]=0.317 eV, hν[sub 2]=0.380 eV, and hν[sub L]=0.622 eV. The emission band hν[sub 1] was identified with radiative transitions between electron and hole quantum well subbands in the semimetal channel at the P–GaIn[sub 0.03]As[sub 0.10]Sb/p-InAs interface, while the hν[sub 2] band originates from radiative transitions involving deep acceptor states in the InAs substrate. The high-energy recombination hν[sub L] is characteristic of the Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78] bulk quaternary layer. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]