This presentation demonstrates the utilization of NEMO3D to understand complex experimental data of embedded InAs quantum dots that are selectively overgrown with a strain reducing InGaAs layer. Different alloy concentrations of the strain layer tune the optical emission and absorption wavelength of the quantum dots. The role of the non-linear strain behavior ovserved in the experimental data is explored in NEMO3D. The simulation engine serves as a virtual microscope to understand the interplay of disorder, strain, and quantum dot shape.
- Optical emission at 1.5μm without GaN
- Understand experimental data on QD spectra in selective overgrowth
- Model large structure
- 60nm x 60nm x 60nm
- 9 million atoms
- No changes to the published tight binding parameters
- Match experiment remarkably well
- change in quantum dot aspect ratio
- Quantitative model of complex system
- Studied sensitivity to experimental imperfections – small variations
- Effective mass theories provided the wrong guidance
Researchers should cite this work as follows:
Gerhard Klimeck; Muhammad Usman (2010), "Nanoelectronic Modeling Lecture 32: Strain Layer Design through Quantum Dot TCAD," https://nanohub.org/resources/9272.
Università di Pisa, Pisa, Italy