All Questions
Tagged with semiconductors physics
42
questions
1
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7k
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Does doping always increase the conductivity of a semiconductor?
The conductivity of a semiconductor is given as (if extrinsic):
\$\sigma = qnu_e + qpu_h\$
where \$\sigma\$ is the conductivity, \$u_e\$ and \$u_h\$ are the electron and hole mobilities.
But does ...
- 45
0
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3
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3k
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Electron concentration in an intrinsic semiconductor at room temperature
For a Si atom, band gap energy is around 1.1 eV which means that an electron in valence band needs at least this much energy to jump to conduction band.
Also, at room temperature, typically energy of ...
- 11
0
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1
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116
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Unusual informations of PN-diode
There are several variables like: concentration of electron deficiencies/holes or electrons (n,p) in p/n-type of semiconductor, concentration of donor or acceptor atoms (Nd,Na) in doped semiconductors,...
- 2,432
2
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2
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1k
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Why is the gradient of Energy vs. wavenumber(k) zero at the edge of Brillouin zones?
My question relates to semiconductor physics. The relationship between energy E and wavenumber k for the Kronig-Penny model looks like this, where a is the period of the potential function:
I am ...
- 145
1
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1
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140
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When do the holes in semiconductor appear?
I'm trying to understand the concept of semiconductors, as far as I know whenever an electron moves it leaves a hole, so how can we say (for example) that n-type semiconductor has a majority of \$e^-\$...
- 113
0
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1
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99
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Semiconductor Conduction
I've read that semiconductors (i.g. intrinsic silicon) behave as insulators at absolute zero (since all valance electrons are shared via neighboring atoms). My question is, does conduction still take ...
- 129
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1
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95
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Finding depletion region without built in potential
I am trying to solve a problem as to find the depletion region's width of a p+-n-n diode. I am given the width of the first n region and the doping of both n regions.
Here is the problem:
I believe ...
- 157
0
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2
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3k
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Relation between drift velocity & conductivity of a doped semiconductor
Here is the problem, and I am stuck.
When an electric field with strength \$1 \times 10^3 \text{V/cm}\$ is
applied to a p-type uncompensated Si sample at room temperature, the
electron drift ...
- 285
5
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4
answers
699
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In a semiconductor, why is it said that holes also diffuse?
Let's say we have a p-type and an n-type semiconductor. I understand that the free electrons in the n-type semiconductor move to the p-type, but why is it said that the holes also move to the n-type ...
- 377
2
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4
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6k
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What exactly is a potential barrier in transistors?
Here it says that:
When a transistor is OFF, there exists a potential barrier between the source and the drain..
I don't know exactly what a potential barrier is. If I had to make an educated ...
- 377
2
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1
answer
477
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Potential drops in BJT in CE configuration?
In a simple p-n junction diode, there is a \$V_{eq}\$, the potential difference between the p-doped and the n-doped portion of the diode. When an external potential \$V\$ is applied in forward bias, ...
- 169
2
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1
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389
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Physics/chemistry understanding of PMOS and NMOS to form CMOS
Can anyone provide me explanations or links that provide a clear explanation of what atoms/molecules are in p-type and n-type (PMOS/NMOS) and how they interact to create actions?
- 481