All Questions
Tagged with semiconductor-physics electronics
249
questions
0
votes
1
answer
62
views
I don't really get transistors. How do they work exactly in the active region?
So in an NPN transistor, when the base-emitter is forward biased, and the base-collector is reversed biased, electrons from the emitter get to the base. That part I understand, electrons are the main ...
0
votes
1
answer
37
views
How can charge neutrality be maintained for a forward-biased PN junction?
When a PN junction is forward biased, majority electons diffuse into p region and majority holes diffuse into n region, if we impose quasi-neutrality, then we have that in the p and n regiosn the ...
0
votes
0
answers
40
views
Would a diode more ideal than Shockley diode equation violate the second law of thermodynamics?
The Shockley diode equation describes the behavior of all diodes extremely well. Semiconductor p-n diodes and Schottky diodes are described by the very same equation. Furthermore, it applies to light ...
- 123
0
votes
0
answers
72
views
Current due to Ambipolar transport of excess carrier in semiconductors
I am reading Neaman's textbook and I am confused by the ambipolar transport phenomenon. According to what I have understood, if excess carriers are injected somehow into a doped semiconductor piece, ...
0
votes
0
answers
27
views
Minority-carrier only injection into bulk semiconductor
If an n-type bulk semiconductor sample was injected from the side with holes. Such that holes are injected uniformly into a small region near the side surface of the sample. Does this excess minority ...
0
votes
1
answer
65
views
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 ...
0
votes
1
answer
38
views
For intrinsic semiconductors, is the gap Energy equals $E_c-E_v$ or $E_c+E_v$?
So I have a problem with the intrinsic Fermi Level because by definition it is in the middle of the gap energy, and knowing that Eg=(Ec-Ev), we should have Ei=(Ec-Ev)/2.
But when we follow the ...
2
votes
1
answer
49
views
How a switching mixer works in this example circuit?
I am reading about lock-in amplifiers and came across this example circuit of a mixer:
You have one sinusoidal input signal $e_1$ with a phase $\phi_1$ and the local oscillator has a square-wave ...
- 229
0
votes
1
answer
77
views
Saturation region of common emitter BJT
About the saturation region of common emitter Bjt it's written that
In saturation mode both of the "diodes" in the transistor are forward biased. That means V(BE) must be greater than 0, and ...
- 1,441
0
votes
1
answer
38
views
When forming an n channel in an N MOSFET, do the pn junctions of the drain-substrate and source-substrate parts disappear?
When forming an n channel in an N MOSFET,, do the pn junctions of the drain-substrate and source-substrate parts disappear?
Here's what I expected:
When gate voltage (higher than threshold voltage) ...
- 107
0
votes
1
answer
50
views
Is the direction of base current always constant in a BJT transistor?
Is the direction of base current always constant in a BJT transistor?
Excluding the transistor breakdown state, is the direction of the base current always the same in the four modes: active mode, cut-...
- 107
2
votes
1
answer
155
views
Voltage across the diode?
Why the voltage across an ideal pn junction diode remains 0.7 volts, even when the applied voltage exceeds 0.7 volts? Shouldn't it be the applied voltage minus the 0.7 V?
- 1,441
2
votes
0
answers
69
views
If an atom loses electron, it becomes a cation; it does not form a hole. However, when electron is lost from a bond, it forms a hole and not a cation
If an atom loses an electron, it becomes a cation, and when an electron is lost from a bond, it forms a hole. This is what the professor told the class, but I am not able to find the reason for that ...
- 21
-2
votes
1
answer
68
views
Why we are using coupling capacitor in AC amplifier? [closed]
Why we are using coupling capacitor in AC amplifier?
-1
votes
2
answers
179
views
Working of transistor
For the operation of the transistor, the base-emitter junction is forward-biased and the Base collector junction is reversed-biased. Due to the concentration gradient, electrons from the N side (...
