Molecular beam epitaxial growth and optical properties of strained rectangular and asymmetric triangular InGaAs quantum well structures

We present the growth and optical properties of rectangular and asymmetric triangular strained layer quantum well (QW) structures involving In x Ga 1- x As. The growth, as monitored by reflection high energy electron diffraction (RHEED), indicated some form of surface disorder and a two-dimensional growth mode throughout. In addition, the surface morphologies suggest no lattice relaxation and hence no strain-relieving defects in the layers. The low temperature photoluminescence (PL) spectra for the various QW structures were dominated by a single feature attributed to the n = 1 electron to heavy hole excitonic recombination. The linewidth for a single 50 Å In 0.13Ga 0.87As/GaAs QW was measured to be 1.8 meV, indicative of high quality InGaAs material as well as smooth heterointerfaces. Also observed are higher PL intensities for the asymmetric triangular MQWs as compared to the rectangular well case.