Physics of exciton wave function in strain-engineered metamorphic InAs/InxGaAs1-x/GaAs quantum dots for telecommunications wavelengths (1.3 - 1.6 ?m)

We probe exciton confinement in strain-engineered metamorphic InAs/InxGaAs1-x/GaAs quantum dots (QDs), promising candidates for lasers operating at telecommunication wavelengths (1.3 - 1.6 ?m). InAs QDs are embedded in a metamorphic lower confining layer (LCL) and a metamorphic upper confining layer (UCL), using GaAs as a substrate. The wavelength emission is tuned by controlling two independent parameters: In content, x, in confining layers (CLs) and LCL thickness, d [1]. The former changes the band offset between QD and CLs and also affects QD-CL mismatch, f, which determines strain, while the latter only affects f. We have studied 31 such InAs/InxGa1-xAs/GaAs QD samples at 2 K using photoluminescence (PL) in magnetic fields, B, up to 15 T. Excitonic model [2] was used for results analysis. This allows us to probe properties of the exciton wave-function, and hence study the confinement of carriers in the dots.