Interface characterization of InAs/AlSb heterostructures by far infrared optical spectroscopy
Grenzflächencharakterisierung von InAs/AlSb Heterostrukturen mit optischer Fern-Infrarot-Reflektions-Spektroskopie
We present high resolution measurements of the far infrared reflectance and absorbance of InAs/AlSb type II heterostructures, grown on GaAs substrates by molecular beam epitaxy. Quantum wells grown with AlAs-like interfaces show broadening and blue shifting of the InAs transverse optical (TO) phonon compared to samples with InSb-like interfaces. This is explained by incorporation of arsenic in the AlSb barriers. The InSb-interface mode, recently reported from Raman investigations, could be observed in the multiple quantum well. Two lines are observed, which are attributed to the normal (AlSb on InAs) and the inverted (InAs on AlSb) interfaces.