All Questions
Tagged with density-of-states semiconductor-physics
19
questions
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Change in internal chemical potential of electrons in the 2DEG
I was reading about quantum capacitance and came across the following formula:
$$\Delta \mu = \frac{N}{\rho}$$ where N is the number of electrons moved from the metal to the low-density-of-states ...
- 202k
1
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0
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176
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Is the Joint Density of States (JDOS) of silicon non-zero below the direct gap?
Given by my band diagram (made using the tight-binding $sp^3s*$ method), does my JDOS make any sense?
I have calculated the JDOS using all possible direct transitions between the valence bands and the ...
- 202k
1
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0
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88
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The DOS effective mass
If we consider the spin-orbit coupling in semiconductors, it is known that the degeneracy of the valance band is lifted up and we got 2 sub-bands the light hole and the heavy hole that are still ...
- 58.7k
0
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1
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550
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Is there a relation between density of states (DOS) and carrier mobility in semiconductors?
By changing DOS, mobility how to change?
What is the relationship between DOS and mobility, if there is?
CommunityBot
- 1
0
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1
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110
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Allowed energy levels in an $E$-$k$ diagram
For a particle confined in an infinite potential well in 1D, the $k$ value is quantized as $k=nπ/a$, where $a$ is the length of the region where $V(x)=0$. However, the $E$-$k$ diagram derived from ...
- 13.5k
4
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6k
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What is the difference between the joint density of states and the density of state?
I think I understood the density of states, but I didn't understand the joint DOS. What is the main difference? What is the exact definition of the joint DOS?
When do we use the joint DOS and when do ...
2
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5
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6k
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Band structure and Density of states (DOS)
Can someone explain how these two plots are related?
How are the peaks in the right are associated with the left figure?
0
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1
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432
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Density of states in a 1D infinite potential well [closed]
The question I have is how would I go about finding the density of states $\frac{dn}{dE}$ of an electron in a 1D infinite potential well with a width of $a$?
I'm only just starting my quantum physics ...
- 4,206
1
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117
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Limits of integration on density of states in semiconductor
The density of electron states in a 3D semiconductor is given by $\rho(E)=\frac{1}{2\pi^2}\left(\frac{2 m^*}{\hbar^2}\right)^{3/2}\sqrt{E}$, derived commonly as shown here. I'm trying to understand ...
- 13
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586
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Effective density of states $N_c$ at different temperature for $\rm Si$
For Silicon at room temperature, Nc = 2.8x10^19 per unit volume. For 300K, m*/m = 1.81 for Silicon. Now Nc is proportional to 1.5th power of both temperature and m* (effective mass). So, at any other ...
- 202k
2
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46
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Show that the effective carrier density for electrons is $2\left(\frac{{m_c}^*k_BT}{2\pi\hbar^2}\right)^{3/2}$ [closed]
The 3-dimensional free electron density of states (DOS) including spin degeneracy is:
$$g(E)=\frac{1}{2\pi^2}\left(\frac{2m_e}{\hbar^2}\right)^{3/2}\sqrt{E}$$ where $m_e$ is the electron mass, and $E$ ...
- 237
0
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1
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61
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$dE$ stands in my way to know the density of states in bulk crystal, how to get rid of it?
In a book about semiconductors, I found the following formula for the density of states:
$$D(E)dE=\frac{(2m)^{3/2}E^{1/2}}{2\pi^2\hbar^2}dE. \tag{1}$$
In that book, the important lesson from this ...
- 202k
0
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1
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531
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Density of States for a quantum well: Derivation?
Consider a quantum well, where we have:
$E_{k_x,k_y,n_z}=\frac{\hslash^2k_x^2}{2m}+\frac{\hslash^2k_y^2}{2m}+f(n_z)$
with $k_x$ and $k_y$ having widths of $\frac{2\pi}{L}$ and $n_z$ varing in ...
- 202k
0
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0
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245
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What is the density of states $SiO_2$?
We build the model by the finite element method. In our model here is silicon dioxide (SiO2). To carry out calculations, it is necessary to know the density of states and the effective mass.
Question:...
- 202k
0
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1
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Fermi Dirac distribution and degenerate energy states
In Quantum Mechanics and in semiconductor materials, the number of electrons $N$ in conduction band is usually computed as follows:
$$N = \int_{E_c}^{+\infty} g_c(E)f(E)dE$$
where $g_c(E)$ is the ...
- 131k
1
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1
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502
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Density of states from $k$ to $E$
Speaking about Quantum mechanics, considering the "particle in a box" condition as an approximation of the electrons condition in a semiconductor, let the material be represented by a volume $V$ with ...
- 10.9k
1
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0
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375
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Calculate 2D Effective mass from bulk effective mass
I am trying to create a self consistent Shrodinger Poisson Solver for various semiconductors. There is already one done by Professor Hu from UC Berkeley - QM CV Simulator.
Looking at the code, they ...
- 202k
2
votes
1
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149
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How does phonon scattering change the distribution function?
For a one-dimensional structure, we know that the modified distribution function has the following energy dependency in equilibrium:
\begin{equation}
Z(\varepsilon)\,f(\varepsilon) = \dfrac{N_\text{1D}...
- 4,135
2
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1k
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3D Density of states
I have the following dispersion relation:
$$\epsilon(\vec{k})=\frac{\hbar}{2}\left(\frac{k_x^2}{m_1}+\frac{k_y^2}{m_2}-\frac{k_z^2}{m_3}\right)$$
(note the minus sign in the third term). And I am ...
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