Effective mass estimation

In summary, effective masses of electrons and holes can be estimated from the band structure. This can be achieved by extracting energy distribution curves and fitting them with a Voigt function, then plotting the peak maxima against crystal momentum and fitting the data points. Alternatively, for materials like Si, the effective mass can be calculated using the semiclassical model by taking the second derivative of the band structure.
  • #1
Ravian
42
0
can we estimate effective masses of electron and hole from the band structure if yes how? can somebody explain with reference to Si band structure?
 
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  • #2
dear ravian,

yes, you can extract the effective mass from your bandstructure.
I you have a bandstructure E(k) you can extract energy distribution curves (take the program IGOR for instance) for the momentum range of interest, e.g. E(k1),E(k2) and so on.
These photoemission peaks you can then fit with a voigt function. From this fit you can
extract the peak maxima and plot them versus the crystal momentum. In a last step you can fit these data points assuming a dispersion E = hbar^2*k^2/(2m*)
 
  • #3
Ravian said:
can we estimate effective masses of electron and hole from the band structure if yes how? can somebody explain with reference to Si band structure?

fk08 said:
dear ravian,

yes, you can extract the effective mass from your bandstructure.
I you have a bandstructure E(k) you can extract energy distribution curves (take the program IGOR for instance) for the momentum range of interest, e.g. E(k1),E(k2) and so on.
These photoemission peaks you can then fit with a voigt function. From this fit you can
extract the peak maxima and plot them versus the crystal momentum. In a last step you can fit these data points assuming a dispersion E = hbar^2*k^2/(2m*)

Oh no! It doesn't have to be THAT difficult.

Once you have the band structure, if you are using the semiclassical model (which you can get away with if you are dealing with Si), then the effective mass corresponds to the second derivative of the band structure, i.e.

[tex]m^* = \hbar^2 \frac{d^2E}{dk^2}^{-1}[/tex]

where E is your band structure dispersion.

Zz.
 

1. What is effective mass estimation?

Effective mass estimation is a method used in physics to determine the effective mass of particles or bodies in a given system. It is an important concept in solid-state physics and is used to describe the behavior of electrons in a crystal lattice.

2. How is effective mass estimated?

Effective mass is typically estimated through experimental measurements or theoretical calculations. Experimental methods involve measuring the response of a particle or body to an external force, while theoretical methods use mathematical models to predict the effective mass based on known parameters.

3. Why is effective mass important?

Effective mass is important because it allows us to simplify the complex behavior of particles in a system and make predictions about their properties and interactions. It is also crucial in understanding the electrical and thermal conductivity of materials, as well as their optical and magnetic properties.

4. What factors affect effective mass?

The effective mass of a particle is affected by several factors, including its momentum, energy, and the strength of the interaction with its surroundings. It can also be influenced by external factors such as temperature, pressure, and the presence of impurities or defects in the material.

5. How is effective mass used in practical applications?

Effective mass has numerous practical applications in fields such as semiconductor technology, where it is used to design and optimize electronic devices. It is also used in the development of new materials for various applications, such as solar cells and computer memory devices.

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