Investigation of strain-modulated InGaAs nanostructures by grazing-incidence x-ray diffraction and photoluminescence

A strain-induced lateral periodic charge carrier confinement is achieved wi thin an LnGaAs single quantum well (SQW) by lateral patterning of an InGaP stressor layer. The one-dimensional periodicity of the long-range strain fi eld is obtained by etching a lateral surface grating into the initially pse udomorphicly strained InGaP layer, while the SQW itself remains unaffected by etching. Grazing incidence x-ray diffraction was applied to analyse the depth variat ion of the in-plane strain field within the nanostucture. The measured inte nsity profiles are discussed in terms of a strain distribution model, creat ed by finite-element calculations using a linear elasticity theory approach . By photoluminescence a strain-induced shift of the SQW electronic band le vels was verified. In particular a splitting of the SQW emission line was f ound, caused by the differently strained parts of the SQW. The photolumines cence results are compared to band structure calculations using a deformati on potential ansatz.