Holes heavier than Electrons?

In summary, holes in semiconductors are generally heavier and less mobile than electrons because they represent the movements of a number of electrons rather than just one. This is due to the concept of effective mass, which takes into account the tendency of an electron to jump from atom to atom in a particular direction, resulting in an effective mass that is several times that of a free electron. This can be further explained by discussing the tensor or scalar expressions for the effective mass.
  • #1
Cheetox
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0

Homework Statement


give a simple argument which will explain why holes in semiconductors are generally heavier and less mobile than electrons.


Homework Equations





The Attempt at a Solution


Is it something to do with the fact that the hole represents the movements of a lot of electrons rather than just one?
 
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  • #2
No, a hole is what's left behind when an electron leaves an atom. It's just a charged atom.
 
  • #3
Ok so how do you then explain why holes are generally heavier?
 
  • #4
I'm not sure really but perhaps you should talk about it being an effective mass as opposed to a real mass which is determined by the tendency of an electron to jump from atom to atom (in a particular direction) and that this gives rise to effective masses that are often several times that of a free electron? Sorry if this is too crude an answer but that's the kind of direction I would go in.

Maybe you should back this up with a discussion of the tensor or scalar expressions for the effective mass.

Does anyone disagree?
 
  • #5
ideasrule said:
No, a hole is what's left behind when an electron leaves an atom. It's just a charged atom.

The first sentence is correct. The second sentence is not. The hole is not the charged atom, it is the empty space on the charged atom that once contained an electron. When a hole moves it is not the charged atom that is moving; the hole moves by virtue of an electron from another atom leaving that atom to fill the hole, but in effect leaving another hole in its original atom. This is how the hole propagates, so the suggestions that you should compare the electron mass to the mass of the atom it leaves behind is misleading - it gives the impression that the hole mass should be the atom's mass minus an electron, which I doubt is true.
 
Last edited:

1. What are holes heavier than electrons?

Holes are the absence of an electron in an atom's valence band. They are essentially positively charged carriers that behave like particles and have a higher mass than electrons.

2. How are holes created?

Holes can be created in an atom's valence band when an electron is excited to a higher energy level, leaving behind an empty space. They can also be created in semiconductor materials through the process of doping.

3. How do holes differ from electrons?

Holes have a positive charge and behave like particles with a higher mass, whereas electrons have a negative charge and behave like waves with a smaller mass. Additionally, holes move in the opposite direction of electrons in an electric field.

4. What is the significance of holes in semiconductors?

In semiconductors, the movement of holes plays a crucial role in the conduction of electricity. They are responsible for creating an electrical current when an electric field is applied to the material.

5. Can holes be used in technology?

Yes, holes are used in various electronic devices such as transistors, diodes, and solar cells. They are also being studied for use in quantum computing and other emerging technologies.

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