Undergrad Exciton Bohr Radius: What is It & Why Does it Matter?

Click For Summary
The exciton Bohr radius represents the average distance between an electron and a hole in an exciton, influenced by kinetic energy and Coulomb interaction. It can be calculated similarly to the Bohr radius of a hydrogen atom, but using the effective masses of the electron and hole. In quantum dots, confinement can reduce the distance between the electron and hole, enhancing Coulomb interaction and leading to discrete energy states. The concept of "no center-of-mass motion" refers to the simplification in calculations where the motion of the exciton is considered without accounting for the combined motion of the electron and hole as a single entity. Understanding the exciton Bohr radius is crucial for applications in nanotechnology and semiconductor physics.
bluejay27
Messages
67
Reaction score
3
What is the exciton Bohr radius? I understand that the exciton is the paired distance of an electron and hole. How does the Bohr radius play a role in this?
 
Physics news on Phys.org
The Bohr radius can be calculated for the Hydrogen atom. To make the translation to an exciton, replace the effective mass by the effective mass of the electron and hole.
 
So for a quantum dot, how can the nanoparticle be smaller than the exciton Bohr radius?
 
The Bohr radius is the radius you get for a free exciton just by considering kinetic energy and the Coulomb interaction. Of course you can reduce the distance between electron and holes by means of confinement as it is done in quantum dots. This results in enhanced Coulomb interaction and discrete energy states as there is no center-of-mass motion.
 
Cthugha said:
The Bohr radius is the radius you get for a free exciton just by considering kinetic energy and the Coulomb interaction. Of course you can reduce the distance between electron and holes by means of confinement as it is done in quantum dots. This results in enhanced Coulomb interaction and discrete energy states as there is no center-of-mass motion.

what do you mean by no center of mass notation?
 

Thread 'Time rondeau crystals, experimental observations'

A relative asked me about the following article: Experimental observation of a time rondeau crystal https://www.nature.com/articles/s41567-025-03028-y I pointed my relative to following article: Scientists Discovered a Time Crystal That Reveals a New Way to Order Time https://www.yahoo.com/news/articles/scientists-discovered-time-crystal-reveals-180055389.html This area is outside of my regular experience. I'm interested in radiation effects in polycrystalline material, i.e., grain...
View full post »

Similar threads

Undergrad Pure semiconductor Quantum Dots?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Spin and wavefunction of excitons
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Instantaneous dipole moment and orbitals
  • · Replies 2 ·
Replies
2
Views
589
Undergrad Question about the Bohr model of atom and and electron in an orbital
  • · Replies 7 ·
Replies
7
Views
2K
Calculating the Bohr radius or velocity of an excitons
  • · Replies 1 ·
Replies
1
Views
3K
Bohr's model applied to Wannier exciton in indirect gap semiconductors
  • · Replies 1 ·
Replies
1
Views
4K
How does temperature affect excitonic absorption?
  • · Replies 1 ·
Replies
1
Views
3K
Bohr radius of Earth-Sun system
  • · Replies 5 ·
Replies
5
Views
2K
Self Trapped & Charge Transfer Excitons
  • · Replies 7 ·
Replies
7
Views
3K
Inside radius of atomic electron cloud vs Z
  • · Replies 5 ·
Replies
5
Views
4K