Questions tagged [semiconductor-physics]
Semiconductor physics is the branch of solid state physics that focuses on specific properties of semiconductors. It studies dynamics of different perturbations (mainly electrons and holes) in the semiconductor crystal and the ways to harness it in electrical circuits.
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Understanding the Fermi level and the Fermi-Dirac distribution [duplicate]
I'm confused about why the Fermi level is located inside the band gap in semiconductors because it's defined to be the energy level where an electron has a 50% chance to be, but there can't be ...
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What are "electron holes" in semiconductors?
I'm tutoring senior high school students. So far I've explained them the concepts of atomic structure (Bohr's model & Quantum mechanical model) very clearly. Now the next topic to be taught is ...
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Why doesn't current flow in reverse biased diode?
Consider this reverse biased diode :
I read that no or very small current flows in reverse biased diode as depletion layers get widened and huge resistance is offered so no electrons can cross it. ...
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Pn junction voltage drop?
This image from wikipedia, explains that there occurs a potential drop across a pn semiconductor junction, and an electric field confined to the depletion region.
I already know the reason for the ...
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What determines the forward voltage drop for a diode?
I have always had the idea that the forward voltage drop in a semiconductor diode was related in a simple way to the bandgap energies in the semiconductor. However this is apparently not the case:
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rob♦
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Band gaps: are they at the centre or at the edge of the Brillouin zone?
Reading about electronic band structures, I came across the following:
Band gaps open at the edges of the Brillouin zone (BZ), since that is where the Bragg scattering occurs.
I am slightly ...
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What does Fermi level in the band gap mean?
What does it mean that the Fermi level for some semiconductors lie in the band gap?
Is Fermi level definition different from what is know as usual?
We define the Fermi level as the highest level of ...
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Why isn't there a potential difference across a disconnected diode?
I know this question sounds silly, as if there was a potential difference a current would be created when the terminals are connected together and this would mean energy has come from somewhere.
The ...
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Why do $p$-orbitals correspond to the valence band in semiconductors?
Silicon is industry's most famous semiconductor.
Its electron configuration is the following:
It means that the highest energy orbitals are the 3p orbitals (which are only partially filled).
Now, ...
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What is it about the "conduction band" of a material that is distinct from the valence band?
I'm taking a course in nanotech and we're discussing nanoelectronics. This has led to a discussion of conductors, semiconductors, and insulators. I have a number of lovely diagrams explaining the fact ...
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What is the concept of hole in semiconductor physics?
What is a hole? And how should we describe it to study it properly?
Many textbooks refer to it as an empty state that carries a positive charge, but how can an empty state carry a positive charge? And ...
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Reverse bias P-N junction [duplicate]
I am not able to understand why the PN junction does not conduct when reverse biased.
Can't electrons travel from the N side through the power supply to the P side where they can jump from one hole to ...
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The concept of Fermi level
I have read and used the concept of Fermi level previously and this is simply an attempt on my side to better my understanding of it by asking myself various questions. I understand that the fermi ...
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What does the Fermi Energy really signify in a Semiconductor?
In understanding the behavior of semiconductors, I'm coming across a description of the Fermi Energy here and at Wikipedia's page (Fermi Energy, Fermi Level). If I understand correctly, the Fermi ...
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Why absence of electron is called hole?
I am having hard time in understanding the concept of holes:
If there is no electron than how can it be a hole?
For a moment lets assume absence of electron is termed as hole but how can this absent ...
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