All Questions
Tagged with semiconductors physics
42
questions
6
votes
2
answers
3k
views
Depletion Region Capacitance in MOSFET
Hi, I would like to ask about the behavior of a MOSFET as a capacitor, particularly at the onset of inversion/weak inversion - see Fig 2.6(c)
At this stage in Fig 2.6(c), there is positive charge at ...
- 3,145
5
votes
4
answers
699
views
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
5
votes
1
answer
645
views
What is the correct carrier concentration equation to use?
In this book I am reading, it gives the intrinsic carrier concentration as:
\$ n_i = \sqrt{N_c\cdot N_v} \cdot e^{({\frac{-E_g}{2*K*T}})} \$
While another book says the carrier concentration is:
\$ \...
- 341
5
votes
1
answer
367
views
Are there semiconductor materials with hole mobility greater than electron mobility?
Every material I've ever seen has a hole mobility much less than its electron mobility. For silicon, it's by a factor of two or three; for gallium arsenide it's more like twenty. But are there any ...
- 35.2k
4
votes
4
answers
889
views
GaN Vs SiC physic properties
Here is a table which shows the différence between GaN and SiC:
I have no knowledge about physics of components. I have just some bases. In the above table I do not see real difference between SiC ...
- 2,478
4
votes
1
answer
456
views
Estimate temperature for silicon (p-n junction)
I need to estimate the temperature at which p-n junction made of silicon lose it rectifying characteristics. (\$N_A=N_D=10^{15}\,cm^{-3}\$)
\$E_G\$ is independent of the temperature and are 1.12 eV ...
- 423
3
votes
1
answer
270
views
What is equilibrium carrier concentration in a semiconductor? Is it material specific? How to calculate it?
Is equilibrium carrier concentration dependent on doping density? If it is, then how to know how much the doping density should be for a particular semiconductor device?
- 47
2
votes
1
answer
477
views
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
votes
2
answers
1k
views
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
2
votes
4
answers
6k
views
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
votes
2
answers
1k
views
Why does the majority carrier concentration near the junction not decrease under forward bias? (PN junction)
We see that the current due to the majority carrier decreases near the junction as shown above, which means the majority carrier concentration should also decrease since the diffusion current is given ...
- 447
2
votes
1
answer
389
views
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
2
votes
0
answers
192
views
MOSFET gate substrate voltage
In a MOSFET the channel is formed between gate and the body it would sense to use gate body voltage to form the channel. Why is gate source voltage used to form the channel?
2
votes
3
answers
133
views
Is there a way to experimentally separate the effects of gate voltage?
I'm currently doing experiments on new kind of semiconductors. These devices have a body (source, drain) and a top gate.
These devices show a response to gate voltage. The conductance changes with ...
- 21
1
vote
3
answers
704
views
What happens to a computer as it is cooled towards absolute zero?
What happens to the behavior of a conventional circuit using conventional components as it is cooled towards absolute zero?
To make this question more relatable: What would happen as we cool a modern ...
- 2,432