Quantum Dots: Artificial Atoms & Molecules in the Solid-State

By Rajib Rahman

iNEMO Group, Purdue University, West Lafayette, IN

Published on

Abstract

Quantum dots are artificial atoms in the solid-state occurring in a variety of size and shape, and can be realized in a variety of materials. Electrons and holes in quantum dots are confined in three dimensions typically by the junction of two different materials or by geometric or electrostatic confinement. Unlike other solid-state systems, quantum dots do not have any periodicity, and are characterized by a set of discrete energy levels and localized wave functions analogous to atoms. Quantum dots have found a variety of applications, including light-emitting diodes, photo-detectors, solar cells, quantum computing, logic devices, medicine and biology, to name a few. In this lecture, I will describe how quantum dots are similar to atoms in the periodic table, with the exception that these artificial atoms can be engineered to suit the needs of various applications. Starting from the quantum mechanics of the Hydrogen atom, I will describe two simple models of quantum dots: the particle in a box, and the quantum harmonic oscillator. I will describe experiments that show evidence of shell structure in quantum dots analogous to multi-electron atoms. I will also describe several applications, which rely on the customized properties of quantum dots. Lastly, I will describe how electron transport in a quantum dot differs from that of a solid-state transistor, and introduce the phenomena of Coulomb Blockade.

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Cite this work

Researchers should cite this work as follows:

  • Rajib Rahman (2014), "Quantum Dots: Artificial Atoms & Molecules in the Solid-State," http://nanohub.org/resources/21342.

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Location

Birck Technology Center, Room 1001, Purdue University, West Lafayette, IN

Quantum Dots: Artificial Atoms & Molecules in the Solid-State
  • Quantum Dots: Artificial Atoms & Molecules in the Solid-State 1. Quantum Dots: Artificial Atoms… 0
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  • Bulk Semiconductors 2. Bulk Semiconductors 74.341007674341014
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  • Semiconductors under confinement 3. Semiconductors under confineme… 260.42709376042711
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  • Semiconductors under confinement 4. Semiconductors under confineme… 390.65732399065735
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  • Quantum Dots Defined by Geometry 5. Quantum Dots Defined by Geomet… 442.64264264264267
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  • Gate Defined Quantum Dots 6. Gate Defined Quantum Dots 530.39706373039712
    00:00/00:00
  • Hydrogen Atom 7. Hydrogen Atom 628.661995328662
    00:00/00:00
  • Hydrogen Atom: Wavefunctions 8. Hydrogen Atom: Wavefunctions 798.66533199866535
    00:00/00:00
  • Hydrogen Atom: Quantum Numbers 9. Hydrogen Atom: Quantum Numbers 831.16449783116457
    00:00/00:00
  • Multi-electron Atoms 10. Multi-electron Atoms 954.38772105438773
    00:00/00:00
  • Simplest QD: Particle in a box 11. Simplest QD: Particle in a box 1009.2425759092427
    00:00/00:00
  • QD model: Quantum Harmonic Oscillator 12. QD model: Quantum Harmonic Osc… 1169.4694694694695
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  • Evidence of atom-like structure: Shell filling in QDs 13. Evidence of atom-like structur… 1230.6973640306974
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  • QDs are customized atoms 14. QDs are customized atoms 1351.9185852519186
    00:00/00:00
  • Multiple QDs: Artificial Molecules 15. Multiple QDs: Artificial Molec… 1372.0720720720722
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  • Applications of QDs: Light-Emitting Diodes/Lasers 16. Applications of QDs: Light-Emi… 1417.3173173173175
    00:00/00:00
  • Applications of QDs: Solar Cells/Photo detectors 17. Applications of QDs: Solar Cel… 1533.6670003336672
    00:00/00:00
  • Applications of QDs: Quantum Computing 18. Applications of QDs: Quantum C… 1616.1494828161497
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  • Applications of QDs: Logic Devices 19. Applications of QDs: Logic Dev… 1701.7684351017686
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  • Applications of QDs: Biology 20. Applications of QDs: Biology 1781.6149482816149
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  • QD Modeling with NEMO 21. QD Modeling with NEMO 1862.0620620620621
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  • Electron Transport: Measurement of current-voltage 22. Electron Transport: Measuremen… 1928.7287287287288
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  • Electron Transport: QD 23. Electron Transport: QD 2139.5061728395062
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  • Device Schematic 24. Device Schematic 2189.3893893893896
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  • Device Schematic 25. Device Schematic 2317.7510844177514
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  • Device Schematic 26. Device Schematic 2443.376710043377
    00:00/00:00
  • From Theory to Reality 27. From Theory to Reality 2468.4351017684353
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  • From theory to reality: Simulation Ingredients 28. From theory to reality: Simula… 2486.51985318652
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  • Summary 29. Summary 2524.1574908241578
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