What Are Excitons and Their Bohr Radius in Semiconductors?

  • Context: Graduate 
  • Thread starter Thread starter timmyeatchips
  • Start date Start date
  • Tags Tags
    Semiconductors
Click For Summary
SUMMARY

Excitons in semiconductors are defined as bound electron-hole pairs, exhibiting significant Coulomb interaction energy. The Bohr radius of a silicon exciton is approximately 5nm, representing the mean distance between the electron and hole, analogous to the hydrogen atom model. This radius is derived from the Rydberg-type model, which applies to excitons in terms of their energy and orbital states. Understanding these concepts is crucial for exploring exciton dynamics in semiconductor materials.

PREREQUISITES
  • Understanding of excitons and their role in semiconductor physics
  • Familiarity with Coulomb interaction and binding energy concepts
  • Knowledge of the Rydberg model and its application to quantum systems
  • Basic principles of semiconductor materials, particularly silicon
NEXT STEPS
  • Research the properties and applications of excitons in GaAs quantum dots
  • Study the implications of exciton binding energy on semiconductor performance
  • Explore the role of near-field optical mapping in exciton wave function analysis
  • Investigate the relationship between excitons and other quasiparticles in condensed matter physics
USEFUL FOR

Physicists, materials scientists, and engineers working in semiconductor research and development, particularly those focused on exciton dynamics and their applications in optoelectronic devices.

timmyeatchips
Messages
6
Reaction score
0
With regards to semiconductors - am I correct in thinking the term 'exciton' refers to an electron/hole pair?
Also what does it mean when I am told that the Bohr radius of a silicon exciton is 5nm - how can such an entity have a set radius?
 
Physics news on Phys.org
Yes, this is correct. See http://www.wordiq.com/definition/Exciton for instance.
The radius correspond to the mean distance between the electron and the hole I guess.

www.iapp.de/~mi-hoffm/spex/ExModels/exmodels.html[/URL]
[url=http://focus.aps.org/story/v12/st15]The Travels of An Exciton[/url] about
Near-field Optical Mapping of Exciton Wave Functions in a GaAs Quantum dot
K. Matsuda, T. Saiki, S. Nomura, M. Mihara, Y. Aoyagi, S. Nair, and T. Takagahara
Phys. Rev. Lett. 91, 177401
 
Last edited by a moderator:
This should have been posted in Atom, Molecules, and Solids, since it's a condensed matter problem.

An exciton is indeed an electron-hole pair. The reason why there is a "Bohr radius" for it is because this is simply a hydrogenic "atom", i.e. you have an negative charge (the electron) being bound by a central positive charge (the hole). So the Rydberg-type model applies to such exciton as far as the energy-orbital states are concerned.

Zz.
 
Excitons

Excitons are indeed an electron-hole pair, and the important feature here is that they are correlated. I.e., there is a significant Coulomb interaction energy, and they are bound such that to separate them, one must supply an energy equivalent to the "exciton binding energy".
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
10K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K