All Questions
Tagged with semiconductor-physics crystals
49
questions
3
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0
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52
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Born–von Kármán (BvK) Supercell
I have come across in the literature Born–von Kármán (BvK) Supercell, which are described as a unit cell that is repeated periodically. However, say in a calculation that is derived using a BvK ...
- 155
1
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1
answer
103
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Interpretation of velocity in the de Broglie wavelength of an electron in a crystal
The de Broglie wavelength of a free electron is $\lambda = h/mv$ whre m is the free electron mass, and v is the velocity. Often in introductory solid state physics literature (review articles, lower-...
- 116
0
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0
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46
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Anisotropy of the effective masses in semiconductors
Recently, I have received a referee report on my paper in which reviewer states the following: "... in all known direct band gap semiconductors the electron effective mass is isotropic or has a ...
- 1
0
votes
1
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41
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Basics regarding $k$-space axis and Energy graph in direct semiconductor
We can see from the graphic axes, that energy increases along the y-axis, and k space increases along the y-axis. Considering a direct or indirect semiconductor whichever it doesn't matter, but why ...
- 3
1
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1
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38
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In semiconductors, can distant particles in the same $k$-space recombine? Is this a wave phenomenon, ignoring physical separation?
I'm trying to understand recombination in semiconductors from a wave perspective. I'm considering the wave vector $k$ not just as momentum, but as a descriptor of the wave function's phase. In direct ...
- 21
2
votes
1
answer
139
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Integral of diverging function
I'm reading the chapter 10 on excitons of "Quantum Theory of Optical and Electronic Properties of Semiconductors" by Hartmut Haug and and Stephan W. Koch. In the second section of this ...
1
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0
answers
201
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The relation between the energy in semiconductor crystal and wave vector
the solution of kroning-penny model inside the semiconductor crystall was something like this
where this solution can be approximated in the conduction band and valence band by a parabola where
\...
- 301
2
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0
answers
181
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The difference between $E-k$ diagram and simplified Energy band digram
I know form the the Kroning-Penny Model the $E-k$ diagram solution which something like this
or like this
but While dealing with semiconductors we always draw this energy band diagram
My question ...
- 597
2
votes
3
answers
487
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Why the energy of a hole is opposite sign to that of electron?
I'm reading in Chrales kittel solid state physics and while introducing the concept of hole we wrote this
I understand that when there is a missing electron lower in the band the energy of the band ...
- 597
0
votes
1
answer
128
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Why is the impurity level in a semiconductor related to the ionization energy of the carrier?
I am using Kittel's book. It says that the relationship between the distance of donor level to the bottom of conduction band is related to the ionization energy, but it does not say why.
- 123
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491
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Understanding effective mass of electron for different $\rm Si$ orientation (001, 111, 110)
I am somewhat familiar with the the constant energy surface of the conduction band picture for $\rm Si$ in the $k$-space (6 ellipsoids). I am also aware that the size of the ellipsoids measured along ...
- 493
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0
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65
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How do excitons move through a lattice?
If an exciton is a photoexcited electron attracted to the hole in the valence shell it left behind, how does the quasiparticle move around? The hole isn't an actual particle. The hole is an effective +...
- 719
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0
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27
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Why delocalized states cannot exist in 2D systems
In "Topological Insulators and Topological Superconductors" by Bernevig and Taylor, it is written on page 60:
In a seminal paper, Laughlin argued that the presence of
edge modes is an ...
- 592
13
votes
4
answers
2k
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Why are Bloch waves so successful at explaining behavior of electrons in crystals?
The solutions to the time independent Schrodinger equation for a periodic potential are Bloch waves of the form
$$\psi(r) = u(r)e^{ik.r}$$
where $u(r)$ is a periodic function with the same periodicity ...
- 175
0
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1
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124
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Experimental Justification for envelope function approximation
The traditional device picture for describing electron dynamics in conduction bands of semiconductors and heterostructures uses Envelop Function approximation (EFA). The EFA assumes the external ...
- 592