Formation of linear InAs quantum dot arrays on InGaAsP∕InP (100) by self-organized anisotropic strain engineering and their optical properties

Abstract

The formation of linear InAs quantum dot (QD) arrays based on self-organized anisotropic strain engineering of an InGaAsP∕InP (100) superlattice (SL) template in chemical beam epitaxy is demonstrated, and the optimized growth window is determined. InAs QD formation, thin InGaAsP capping, annealing, InGaAsP overgrowth, and stacking in SL template formation produce wirelike InAs structures along [001] due to anisotropic surface migration and lateral and vertical strain correlations. InAs QD ordering is governed by the corresponding lateral strain field modulation on the SL template surface. Careful optimization of InGaAsP cap layer thickness, annealing temperature, InAs amount and growth rate, and number of SL periods results in straight and well-separated InAs QD arrays. The InAs QD arrays exhibit excellent photoluminescence (PL) emission up to room temperature which is tuned into the 1.55μm telecommunications wavelength region through the insertion of ultrathin GaAs interlayers. Temperature dependent PL measurements and the linear polarization behavior indicate lateral electronic coupling of the QDs in the arrays.