Quantum confined stark effect in a Quantum dot

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The following tutorial is based on the article:

Reproduced: Fry, P. W., et al. “Inverted electron-hole alignment in InAs-GaAs self-assembled quantum dots.” Physical review letters 84.4 (2000): 733

The tetrahedral InAs quantum dot, what we have simulated has base length $18nm$, and height $8.5 nm$, which is embedded in a GaAs matrix. In this simulation we embed the DOT in a box of GaAs, and apply voltage on the side of the box, creating an electric field in the box.

When the applied field is zero, then we can see that the lighter electrons wavefunction spreads out in the full tetrahedral. While the heavier hole is spread out just in the base region of the QD as depicted in Figure 1.

Figure 1. Electron and Hole WF separation shows a built in dipole moment.

Because the electron and hole WF functions are spatially separated it creates an internal dipole moment of the pyramid as described in the article. The electric field dependence of the transition energy of the ground state WF-s is plotted in Figure 2, which well matches with the results in the article.

Figure 2. Transition energy dependence on the electric field.

The project file can be downloaded from here

  • physicswiki/semiconductors/qdstarkeffect/quantumcstarkqd.txt
  • Last modified: 2019/04/10 05:23
  • by zoltan.jehn