All Questions
Tagged with semiconductor-physics electric-current
69
questions
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65
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Reverse current
I'm getting started with electronics and couldn't help but wonder about this. When the PN junction diode is reverse biased, P connected to the negative terminal and N connected to the positive ...
2
votes
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74
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How to separate electron and hole mobilities in a intrinsic semiconductor?
I read in textbooks that the electric conductivity of a semiconductor is $\sigma=q(n\mu_n+p\mu_p)$, where $q$ is an electron's charge, $n$ and $p$ are the concentrations of electrons and holes, $\mu_n$...
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69
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Diode confusion
Consider the following diagram
Here, the diode is in forward bias, and allows current to flow. However, I am slightly confused why this is the case. A diode is defined to only allow current to flow ...
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700
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Calculating the ideality factor of a diode
I am carying out a semiconductor related experiment to calculate the ideality factor of a diode via I-V curves, here is the formula:
Shockley Diode Formula
I am trying to find n which is the ideality ...
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195
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Drift current and diffusion current in depletion region of diode at equilibrium
The diffusion current for a diode at the edge of the depletion region is $I_D=I_S(e^{qV_A/VT}-1)$. Under an unbiased condition$(V_A=0)$ at equilibrium, $I_D$ will be $0$. The drift current should be ...
- 135
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83
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Zener diode reverse bias I(V) equation
What is the equation for the reverse bias current in terms of voltage applied? And this even be analytically derived? If so, how to derive it.
I can't seem to find good resources on this topic.
- 513
1
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2
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229
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Excess majority carriers in a PN Junction
Current flow in a PN junction is generally expressed in terms of the excess minority carrier concentrations in a PN junction, i.e. the excess holes on the N side and the excess electrons on the P side....
- 197
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237
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Why is collector-emitter breakdown voltage (open base) lower than the collector-base breakdown voltage (open emitter)?
I need to understand why the collector base breakdown voltage is greater than collector emitter breakdown voltage. Can it be analyzed from the energy band diagram so as to remember it mnemotechnically?...
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2
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61
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Why constant voltage applied to pn-junction produces constant current throughout the junction?
Is this assumption just something that turns out to be experimentally valid or there is at least some mathematical model like Kronig-Penney + some statistical mechanics that is able to give a good ...
- 513
1
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1
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42
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Diode $I$-$V$ characteristic for inverse region
This is the Shockley equation for the current of the diode:
$$I_D = I_S \left( e^{\frac{V_D}{nV_T}} - 1 \right)$$
It is also valid for $V_D < 0$, when this equation tends to be
$$I_D = - I_S$$
...
- 767
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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 ...
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8
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3
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657
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Method of averaging velocities of electron when deriving drift velocity
Here is derivation of drift velocity.
Assume there is a field $\vec{E}$ inside the conductor(wire).
Using equations of motion we can say that for every charge inside the conductor, $$\vec{v_1}=\vec{...
- 364
1
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1
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44
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Why does the diode in this AC circuit activate when $u1(t)$ reaches specifically 3.5V? [closed]
In this circuit I am supposed to create the graph for u2(t) where u1(t)=5*sin(314t) V.
I understand how to get the amplitude of u2(t) and that u2(t) equals the voltage over the 100 ohm resistor when ...
- 13
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57
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How does a resistance connected in series with a zener diode but parallel to the load resistance affect the output voltage? [closed]
The breakdown voltage of A is $6V$ and that of B is $4V$
In this question let's assume that the input voltage is $f(t)$, a linear function of time. It's quite obvious that $V_{\text{output}}=f(t)$ ...
- 125
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48
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What makes of a current in solidstate/semiconductor physics?
If there is some incoming light that has hit electrons of a N-type doped silicon and broke loose these electrons from their covalent bounds and excited them to the conduction band and also excited the ...
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