Micro-Raman imaging and micro-photoluminescence measurements of strain in ZnMgSe/ZnSe microdiscs
Semiconductor microdiscs are promising for applications in photonics and quantum-information processing, such as efficient solid-state-based single-photon emitters. Strain in the multilayer structure of those devices has an important influence on their optical properties. We present measurements of the strain distribution in ZnMgSe/ZnSe microdiscs by means of micro-photoluminescence and micro-Raman imaging. Photoluminescence measurements of microdiscs reveal substantially broadened emission lines with a shift to lower energy at the undercut part of microdiscs, indicating local relaxation in this area. The distribution of the strain in the microdiscs is obtained from an imaging micro-Raman analysis, revealing that the freestanding part of the microdiscs is free of defects.
photoluminescence znse microdisc raman