Absorption coefficient of quantum well

In summary, the quantum well absorption coefficient is calculated by summing over the different transitions and when the photon flux is incident, the absorption spectrum becomes continuous due to the absorption of all photons above a certain energy level in the well.
  • #1
equation M
6
0
we know that the quantum well absorption coefficient is calculated by summing over the electron-heavy hole and electron-light hole transitions:


α[itex]_{w}[/itex](E) = [itex]\sum_{n}α[/itex][itex]_{e_{n}-hh_{n}}[/itex](E) + [itex]\sum_{n}α[/itex][itex]_{e_{n}-lh_{n}}[/itex](E)

where n is the n[itex]^{th}[/itex] transistion.

but when the photon flux is incident on the QW, the absorption spectrum becomes continuous rather than discrete as all the photons above a certain level of energy will be absorbed in the well. Am I right?

please help me ... i am novice in this field.
 
Physics news on Phys.org
  • #2
Yes, you are correct. When the photon flux is incident on the quantum well, the absorption spectrum becomes a continuous curve rather than discrete energy levels due to the fact that all photons above a certain energy level will be absorbed in the well. It is important to note that the absorption coefficient (α_w) still takes into account the electron-heavy hole and electron-light hole transitions, but the absorption takes place at an energy range instead of discrete energy levels.
 

1. What is the absorption coefficient of a quantum well?

The absorption coefficient of a quantum well refers to the measure of how well a material can absorb light at a particular wavelength. It is a crucial parameter in understanding the optical properties of a quantum well, as it determines the material's ability to absorb and emit light.

2. How is the absorption coefficient calculated for a quantum well?

The absorption coefficient of a quantum well can be calculated using the material's absorption cross-section and the density of the quantum well layers. It is also influenced by the material's bandgap energy and the thickness of the well layers.

3. What factors affect the absorption coefficient of a quantum well?

The absorption coefficient of a quantum well is affected by various factors, such as the material's bandgap energy, well layer thickness, and density. It is also influenced by external factors like temperature, electric field, and strain.

4. How does the absorption coefficient change with the size of the quantum well?

The absorption coefficient of a quantum well is highly dependent on the size of the well. As the size of the well decreases, the absorption coefficient also decreases due to the quantum confinement effect. This means that the material's ability to absorb and emit light is significantly influenced by the size of the quantum well.

5. Why is the absorption coefficient of quantum wells important?

The absorption coefficient of quantum wells is essential in various applications, such as optoelectronic devices, solar cells, and lasers. It provides valuable information about the material's ability to absorb and emit light, which is crucial in designing and optimizing these devices for efficient performance.

Similar threads

Replies
3
Views
1K
Replies
12
Views
739
Replies
6
Views
7K
Replies
6
Views
832
  • Quantum Physics
2
Replies
38
Views
3K
  • Quantum Physics
Replies
1
Views
822
  • Quantum Physics
Replies
15
Views
2K
Replies
36
Views
7K
  • Quantum Physics
Replies
8
Views
1K
  • Atomic and Condensed Matter
Replies
9
Views
6K
Back
Top