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We present the results of photoluminescence experiments on InSb/AlxIn1-xSb multi-quantum-wells on GaAs substrates. A comparison of the photoluminescence signals with transmission measurements shows Stokes shifts of 2.8–6.9 meV, indicating that the low temperature luminescence is mainly due to bound excitons localized by interfacial potential minima. The high temperature signal is attributed to ionized free carriers. The well width dependent thermal activation energy investigation indicates that nonradiative carrier loss from the wells to the barriers is not a dominant mechanism. Instead, we suggest that the thermal recombination by surface dislocations or defects might be the main nonradiative channel for high temperature luminescence. [ABSTRACT FROM AUTHOR]

Three types of defects at the surface of InSb quantum well samples are identified: hillocks, square mounds, and oriented abrupt steps. The electron mobility in the quantum well correlates to the density of abrupt features, such that samples with a high density of anisotropic defects show anisotropy in the mobility. We propose that the dominant scattering mechanism associated with these abrupt features is a fluctuation in the quantum well morphology. [ABSTRACT FROM AUTHOR]

InAs/InAs0.865Sb0.135 quantum wells are characterized using magneto-photoluminescence. Band- to-band transitions are found at energies lower than the band gaps of either the InAs or the InAs0.865Sb0.135 with photoluminescence emission at wavelengths up to 4.8 μm. By modeling the quantum size shifts of the photoluminescence transitions and their energy shift in a magnetic field, the valence band offset between InAs and In(As,Sb) is deduced to be type II with electron confinement in the In(As,Sb) alloy and hole confinement in InAs. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We use interband exciton transitions in parabolically graded quantum wells to measure the band offset at the InSb/Al[sub x]In[sub 1-x]Sb interface. The method we use is based on similar studies in the GaAs/Al[sub x]Ga[sub 1-x]As system but modified to reflect the strong nonparabolicity and strain of the InSb/Al[sub x]In[sub 1-x]Sb system. We find a conduction band offset ratio of 0.62±0.04 for Al concentrations in the range 2%-12%. The observed lack of variation of the offset with Al concentration suggests a lack of strain dependence in the InSb/Al[sub x]In[sub 1-x]Sb system for practical Al concentrations. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report the observation of interband exciton transitions in InSb/Al[sub x]In[sub 1-x]Sb multi-quantum-well samples. The exciton peaks are identified with the use of a simple quantum well model. The strain present in the InSb wells alters the spectrum significantly from that for unstrained III–V materials and makes it possible to use the exciton spectrum in determining the band offset. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]