Formation of band gap

  • Thread starter asifmumtaz
  • Start date
band gap arises due to lattice potential.band gap is produced at zone boundary due to bragg reflection.there it behaves like standing wave instead of travelling wave?further formation of 2 standing waves?plz help
 
i tried best to clear my question,
band gap in solids arises due to lattice potential.this lattice potential has max. effect at zone boundary.band gap is produced at zone boundary due to bragg reflection of travelling wave.after reflection it becomes standing wave instead of travelling wave?howz this possible?plz help
 
I'm not an expert, but I here's my opinion:

Yes, bandgap arises from the bragg reflections at the zone boundary. the traveling wave becomes a standing wave - I agree. How is this possible? The mathematical definition of traveling wave is: Amplitude * cos( k * x - omega * t), where k is the wavevector of the wave, omega is its characteristic frequency, x and t are spatial and time coordinates. When traveling wave suffers a reflection off the zone boundary there's an equal but opposite traveling wave (reflected part). By superposition then, the total k of the wave is zero - hence standing wave.
 

Related Threads for: Formation of band gap

  • Last Post
Replies
10
Views
7K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
5
Views
4K
  • Last Post
Replies
1
Views
6K
  • Last Post
Replies
6
Views
10K
  • Last Post
Replies
5
Views
3K
  • Last Post
Replies
15
Views
15K
  • Last Post
Replies
1
Views
4K
Top