Si−doped In0.145Ga0.855As0.123Sb0.877: A novel p−type quaternary alloy with high crystalline quality

Abstract

Antimonide−based p−n junctions are particularly attractive for a wide variety of optoelectronic applications in the near and mid-infrared wavelength range. In this work, novel p−type Si−doped In0.145Ga0.855As0.123Sb0.877 epitaxial layers were grown on GaSb(100) substrates by Liquid Phase Epitaxy (LPE) technique. The XPS spectra measured on Si−doped In0.145Ga0.855As0.123Sb0.877 layers indicate that Si atoms behave as acceptors. The analysis of the surface depletion region and its relationship with phonon−plasmon L_ coupling were investigated using Raman spectroscopy, giving an acceptor concentration of NA ∼ 5.8 × 1017 cm−3 for a depletion region thickness of d ∼ 9.4 nm. Low temperature photoluminiscence (PL) spectrum for the Si−doped In0.145Ga0.855As0.123Sb0.877 layers showed a bound excitonic emission peak associated to neutral Sb acceptors, with an activation energy of ∼10meV and a donor−acceptor transition. It was observed that the Si doping reduces the excitonic emission intensity and increases the donor−acceptor pair recombination intensity.