Fermi Energy & Optical Transitions

In summary, the conversation discusses a question about band structures and interband optical transitions in a two dimensional solid with two electrons per unit cell. The crystal potential is weak and the solid behaves like a free electron metal. The question asks for an estimate of the threshold for interband optical transitions in terms of the fermi energy. The conversation concludes with the individual finding an answer related to band structure and thanking the other person for trying to help.
  • #1
iansullivan88
5
0
Hello,

I have a question which has something to do with band structures etc:

A two dimensional solid has two electrons per unit cell. The crystal potential is weak and the solid behaves like a free electron metal.

Estimate the threshold for interband optical transitions in terms of the fermi energy.


I have no idea where to begin with this really. Any help would be appreciated.

Thanks

Ian
 
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  • #2
iansullivan88 said:
Hello,

I have a question which has something to do with band structures etc:

A two dimensional solid has two electrons per unit cell. The crystal potential is weak and the solid behaves like a free electron metal.

Estimate the threshold for interband optical transitions in terms of the fermi energy.


I have no idea where to begin with this really. Any help would be appreciated.

Thanks

Ian



How much physics have you done?

Do you know the physics behind free electron metals?
 
  • #3
I found an answer now. It was to do with band structure. Thanks for trying to help.

Ian
 
  • #4
iansullivan88 said:
I found an answer now. It was to do with band structure. Thanks for trying to help.

Ian

How did you calculate it in the end?
 

Related to Fermi Energy & Optical Transitions

1. What is Fermi energy?

Fermi energy, also known as Fermi level, is the highest energy level occupied by an electron at absolute zero temperature in a solid material. It serves as a reference point for determining the energy states of electrons in a material.

2. How is Fermi energy related to the number of free electrons in a material?

Fermi energy is directly proportional to the number of free electrons in a material. This means that as the number of free electrons increases, the Fermi energy also increases.

3. What are optical transitions?

Optical transitions refer to the process of an electron moving from one energy level to another by absorbing or emitting light. This phenomenon is commonly observed in semiconductors and is essential for various electronic and optoelectronic applications.

4. How does Fermi energy affect optical transitions?

The difference in energy levels between the initial and final states of an electron during an optical transition is known as the bandgap. Fermi energy plays a crucial role in determining the bandgap and, therefore, affects the energy of light required for an optical transition to occur.

5. Can Fermi energy be manipulated to control optical transitions?

Yes, Fermi energy can be manipulated by changing the material's properties, such as its composition, temperature, and external electric or magnetic fields. By adjusting the Fermi energy, it is possible to control the energy of light required for optical transitions, making it a useful tool in optoelectronic devices.

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