All Questions
Tagged with semiconductor-physics electromagnetism
56
questions
2
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62
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Why defects don't have an effective charge in metals?
In semiconductors and insulators, crystal defects, e.g., vacancies and interstitials, are treated as having an effective charge. In metals, however, defects are treated as neutral. I can expect that ...
- 191
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0
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42
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How can red LEDs still give a faint glow at a voltage of only 1.4V? [duplicate]
How can a red LED work at a voltage of only $1.4{\rm V}$? Red photons have an energy of $1.77{\rm V}$ if we use $\lambda = 0.7\mu\text{m}$ in the relation:
$$ E = \hbar \omega = \frac{2\pi\hbar c}{\...
- 4,913
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Does diffusion current "consume" thermal energy?
My (possibly erroneous) understanding of solid state physic has led me to the belief that diffusion current may "consume" thermal energy.
Here is my (possibly erroneous) understanding. When ...
- 2,882
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38
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Electric Field Far From PN Junction
According to Semiconductor physics and devices Book by Donald A. Neamen book. The electric field far from the space charge region is very small and most of the applied voltage happens across the space ...
- 63
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2
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102
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Definition of Hall's current
Dear fellow physicists!
I come to you with a question regarding the definiton of the Hall current.
The only sentence close to definition of this concept, I have found after extensive search on the ...
- 1
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1
answer
62
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Pn junction and the structure of diodes
I've read the part about pn-junction from Manfred Albach's "Elektrotechnik" book and I've seen some resources online as well. However, there are a few questions that bother me and prevent me ...
0
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1
answer
73
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Confusion regarding on whether to include conduction charges(intrinsic to the material) as a part of bound charges in the calculation of polarization
Consider a semi-conductor in which conduction is mainly due to free electrons(valence electrons that are free to roam throughout the material) , and since it's a semi-conductor say not all atoms ...
- 109
5
votes
2
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302
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How can modern transistors have width of only a few dozen atoms?
We typically analyze transistor's work based on a work of a simple pn-junction diode, with some modifications if needed, as it is basically a particular configuration of pn-junctions. We assume the ...
- 513
2
votes
1
answer
129
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How is electrostatic potential distributed along a circuit element?
Suppose we have a diode circuit like that:
Suppose the voltage has magnitude $\varphi$ and one end of the wire has potential zero.
How will the potential be distributed throughout the diode?
Does $\...
- 513
0
votes
0
answers
62
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Current in primary circuit when diode in secondary circuit is reverse biased
Let's say we have an ideal transformer with a diode in the secondary circuit:
If the diode is reverse biased, there would be no current in the secondary circuit, which would mean that there is no ...
- 3
2
votes
2
answers
676
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I’m trying to charge a capacitor. Would a bridge rectifier charge it like a battery would?
Since a bridge rectifier converts ac to dc. Will this charge my capacitor to max capacity how hooking it up to a battery would? The positive is charging the anode, while the cathode is grounded. Any ...
- 37
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56
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Electric fields and intrinsic semiconductors
If we apply a electric field to a conductor the charges inside move close or away from the electric field which creates a electric field inside the conductor which cancels out the external electric ...
- 105
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1
answer
181
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Thermoelectric Thomson effect as generator
In thomson effect we need an electrical current and a temperature difference at the same time. So it is possible use Thomson effect to generate an electric current? That is, how I generete an electric ...
- 31
1
vote
1
answer
67
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No net generation or recombination of electrons is assumed
I am currently studying the textbook Physics of Photonic Devices, second edition, by Shun Lien Chuang. Section 2.1.1 Maxwell's Equations in MKS Units says the following:
The well-known Maxwell's ...
- 889
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1
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Question about pulse transformer
I understand transformers only work with AC because there is electromagnetic induction only when the current going through is AC. In switch-mode power supplies, the pulse transformers are powered by ...
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