Lateral wavelength control of InAs∕InGaAsP∕InP (100) quantum dots in the 1.55μm region by selective-area metal organic vapor-phase epitaxy

Abstract

We report lateral wavelength control of InAs quantum dots (QDs) embedded in InGaAsP on InP (100) substrates by selective-area metal organic vapor-phase epitaxy (SA MOVPE). The technologically important 1.55μm telecommunications wavelength region is assessed by the combination of ultrathin GaAs interlayers beneath the QDs with proper SiNx mask design. Atomic force microscopy and microphotoluminescence reveal evolution of the QDs formed by 2 ML InAs as a function of growth rate enhancement with pronounced height and density increase, resulting in a wide wavelength tuning range of 110nm. Saturation of QD formation is observed for 3 ML InAs supply producing a much smaller tuning range of only 25nm which is supported by the increasing GaAs interlayer thickness. Hence, two regimes are identified allowing either wide wavelength tuning or wavelength stability of QDs in the 1.55μm region offering complementary applications of the monolithic integration of optoelectronic devices by SA MOVPE.