Near-infrared intersubband absorption in (CdS/ZnSe)/BeTe type-II super-lattices grown on GaAs substrate by MBE

We study the dependence of absorption wavelength on the well width in the (CdS/ZnSe)/BeTe super-lattices(SL). With well-width reduction, the wavelength decreases from 1.795 to 1.57 μm. Structural properties, strain state and interface composition are determined via XRD measurement. A (CdS/ZnSe)/BexMg1−xTe structure is prepared and XRD reveals the average lattice constant match to GaAs substrate. TEM reveals that numerous stacking faults exist in the (CdS/ZnSe)/BeTe structure, and stacking faults are completely suppressed in (CdS/ZnSe)/BexMg1−xTe SLs. Intersubband transition down to 1.535-1.55 μm have been observed in SLs.