Submonolayer stacking growth of In(Ga)As nanostructures for optoelectronic applications: an alternative for Stranski–Krastanov growth

Abstract An overview on the submonolayer stacking (SMLS) growth, by molecular beam epitaxy, is given for the growth of InAs-based quantum dots (QDs) and quantum well islands (QWIs) on GaAs in comparison with Stranski–Krastanov (SK) growth. While the size, shape, and density control of QDs by the substrate temperature or source fluxes has already been demonstrated by SK, SMLS provides novel possibilities due to its higher degree of freedom to control. By SMLS, QDs can be grown with higher size/shape control, and QWIs with varied thickness in disk-like shapes. These structures can be free from a wetting layer, being isolated from each other “floating” in the matrix. More importantly, the induced strain field is tunable, allowing us the opportunity to perform simultaneous strain and bandgap engineering. Our recent results in the tuning of photoluminescence wavelength and the transition from two-dimensional to three-dimensional structures together with atomic force microscopy are shown.