Muhammad Usman

Spectral energy tuning of InAs quantum dots with InGaAs quantum wells

Quantum Dots in Quantum Wells Selective Overgrowth and Wavelength Tuning Muhammad Usman, Gerhard Klimeck

Objective:

  • Optical emission at 1.5um without GaN?
  • Understand experimental data on QD spectra in selective overgrowth

Approach:

  • Model large, realistic structure 60nm x 60nm x 60nm => 15 million atoms
  • No changes to the published tight binding parameters

Results:

  • Match experiment remarkably well
  • Strain is of critical imprtance
  • Change in quantum dot aspect ratio - quantum dot changes shape!

Impact:

  • Quantitative model of complex system
  • nano-TCAD for Quantum Dots!

Publication:

  • Accepted in IEEE Trans. Nanotechn.

Powerpoint slide as ppt, pdf, or as image below.

Muhammad Usman's Pages

Biography Outline NEMO-3D Fine Structure Splitting in QDs Crystal Symmetry, Strain, and Piezo-Electricity Couple Quantum Dot Spectral energy tuning of InAs quantum dots with InGaAs quantum wells Quantitative spectroscopy of bilayer QD molecules for Quantum Information Processing TE/TM Ratio Tailoring of Single and Bilayer QDs for Optical Amplifiers