Experimental and theoretical investigation of the (In0.53Ga0.47As)(1-z) (In0.52Al0.48As) (z) digital alloy

Abstract

We investigate experimentally and theoretically the band structure of the (In0.53Ga0.47As)(1-z) (In0.52Al0.48As) (z) digital alloy grown by using molecular beam epitaxy as a function of z, where z is defined by the thickness fraction of the InGaAs and the InAlAs layers lattice-matched to InP. To calculate the band structures of the InGaAs/InAlAs digital alloy, we used the 4 x 4 k center dot p method; then, we compared these band structures with the photoluminescence experimental results. These experimental and theoretical results show that the InGaAs/InAlAs digital alloy not only can contribute to the method of band-gap engineering by using various types of thickness combinations but also can cover the wavelength gap of 1.2 mu m (1.1 mu m (GaAs) < lambda < 1.3 mu m (InP)), that only the quantum dot can cover. We also propose a quantum-well structure that is able to cover the wavelength gap.