Band offset determination in the strained-layer InSb/AlxIn1-xSb system

We use interband exciton transitions in parabolically graded quantum wells to measure the band offset at the InSb/AlxIn1-xSb interface. The method we use is based on similar studies in the GaAs/AlxGa1-xAs system but modified to reflect the strong nonparabolicity and strain of the InSb/AlxIn1-xSb 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/AlxIn1-xSb system for practical Al concentrations. (C) 2000 American Institute of Physics. [S0003-6951(00)04926-3].