Semiconductor physics is the branch of solid state physics that focuses on specific properties of semiconductors. It studies dynamics of different perturbations (mainly electrons and holes) in the semiconductor crystal and the ways to affect it.
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how does zener diode maintain potential across its terminals?
My physics book has a topic about zener diodes being used as voltage regulators in the reverse bias.
Well, I'm curious to know how does the zener maintain the potential across its terminals after it ...
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Estimation of the internal electric field strength in the pn-junction
I would like to compare my result in an order of magnitude. So, How can I estimate the strength of the electric field in a typical Si PN-junction?
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Carbon in the form of graphite a conductor?
Well, it happens a I have a glucose test strip (One Touch Ultra) which has three electrodes (Counter, Working and Reference) and I'm guessing this electrodes are made from graphite mixed with a ...
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Donors/Acceptors in Metal Oxides
Can anyone explain to me why most articles describe chromium as an acceptor in titanium dioxide? In TiO2, titanium has the charge state Ti$^{4+}$ and oxygen has the charge state O$^{2-}$. When Cr ...
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Are $A$ and $J$ in Black's equation (for electromigration reliability of wires/interconnections) independent?
Black's equation is an empirical model to estimate the MTTF (mean time to failure) of a wire, taking electromigration into consideration. Since then, the formula has been getting popularity in ...
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77 views
How creation of point defects in semiconductors is affected by strain?
When the effect of the strain on solids is discussed, normally the explanation is the following: increasing stress, first point defects created, then dislocations, then plastic deformation starts, ...
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82 views
Semiconductor problem: how much Boron is required to establish a certain amount of charge carrier density
The problem description is as follows:
Boron is used to dope 1 kg of germanium (Ge). How much boron (B) is required to establish a charge carrier density of 3.091 x 10^17 / cm^3. One mole of ...
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105 views
Does anyone know the difference and relation between $k\cdot p$ method and tight binding (TB) method?
Among the methods of calculating energy bands for crystals, first-principles method is the most accurate. Besides first principles, two commonly used modeling methods are the $k\cdot p$ method and ...
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85 views
Constructing Tauc Plots
How can we construct a tauc plot using data from the transmission spectra? How does one calculate the absorption coefficient for plotting tauc plots?
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If we connect a block of p-type semiconductor only to a positive terminal, will it become positively charged?
Connect the positive terminal of a battery to a piece of p-doped semiconductor, say, silicon doped with boron. Will the terminal pull electrons out of the doped silicon, or equivalently, inject holes ...
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142 views
Why do the drift and diffusion components cancel for each type of carrier if EHP generation plays such big role in p-n-junctions?
I have always argued to myself that drift and diffusion components of the current though a p-n-junction cancel for each type of carrier because any electron diffusing from n into p will sooner or ...
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Semi-conductors
Suppose there is a semiconductor with Fermi energy $E_f$ and that there are $N$ bound electron states.
I'd like to know why the mean number of excited electrons takes the form $$\bar n={N\over ...
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Turn-on delay time for Laser diode
Do you know any simple explanation on the reason why the turn-on delay time on a laser diode is reducing while we increase the bias current?
Turn on delay,is the time that the laser needs from the ...
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How did the Bardeen-Brattain point-contact transistor work?
How did the Bardeen-Brattain point-contact transistor work?
What are the conditions under which a Schottky barrier injects minority carriers?
In a bipolar junction transistor the forward-biased ...
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64 views
Electron Relaxation/Polarization for and n-type Semiconductor
Please help me understand the following (general) statement, referring to electrons in a full valence band of an n-type semiconductor:
"An electron filling up the last empty state in the valence band ...
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46 views
Why does silicon have an indirect gap?
Is there an intuitive explanation as to why silicon has an indirect gap? I have heard that this can explained using pseudopotentials.
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Semi-conductors and induced charge
Can a semi-conductor ( germanium or silicon) or a semi-metal ( graphite ) carry an induced charge ?
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What is effective mass approximation
Currently i am studing about quantum confinement in semiconductors and came across effective mass approximation.but i am unable to understand this concept. what is the use of effective mass ...
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Problems in the modern semiconductor/electronics technology?
From what I have read, the problem with modern semiconductors/electronics seems to be quantum tunnelling and heat. The root of these problems is the size of the devices. The electrons are leaking out, ...
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732 views
Fermi-Energy Level for Extrinsic Semiconductor
How to change the Fermi-Energy level for extrinsic Semiconductor with the temperature change?
Thanks,
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1 Mohm Resistivity at cryogenic temperature for doped silicon
I would like to pick the correct doping of silicon to get 1 Mohm cm resistivity at liquid helium temperature of 4.2 K. The metal insulator transition implies that I need a very accurate doping. Are ...
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Orientation in GaAs
I can't find the precise definition of what is the orientation of a GaAs lattice. Being the superposition of two fcc lattices (one of Ga, the other of As), I would think that it is the direction of ...
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331 views
Why is the valence band maximum at the gamma point in the bandstructure view of dispersion relation?
Why is the valence band maximum for most semiconductors at the gamma point in the bandstructure view of dispersion relation
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285 views
Fermi level in disordered amorphous and/or organic semiconductors
So, the Fermi level in crystals is pretty easy to understand. Been using it and talking about it in terms of the highest occupied level forever. However, I'm now reading about disordered systems. A ...
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layered CMOS structure question
I am trying to understand the workings of a CMOS image sensor. I understand that increasing wavelength results in an increased penetration depth in the silicon often used in CMOS image sensors. What ...
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fermi level in equilibrium and nonequilibrium situation
Why do the fermi level for electrons and holes coincide in equilibrium condition and why they separate as quasi fermi levels in non equilibrium situation?
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58 views
Explanation of NMOS processes
So, gate (poly-si + $SiO_2$) and $p^{-}$ silicon operate as capacitator.
But how are voltages and charges are applied? In order for inversion to occur, there should be charges formed in poly-Si, ...
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72 views
Charge Based Capacitance Measurement (CBCM)
I am using Keithley 4200-SCS to measure the device capacitance.In order to get total capacitance of the device, the Gate terminal is voltage biased and the other three terminals are grounded.
I wanted ...
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93 views
Energy efficiency Vs power efficiency
I want to understand if there can be any real difference between the requirement of Energy efficiency and the requirement of power efficiency for a physical system. For example for CMOS-based digital ...
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109 views
How did Shockley, Bardeen, and Brattain get purified germanium and dope it correctly?
They obviously didn't have precision semiconductor fabricating tools themselves running with semiconductor parts inside because there were none. We have so much advanced machinery to weigh out, ...
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386 views
How to determine donor or acceptor impurity
I am working on a practice exam for semiconductor physics. Can anyone help me figure out how to determine whether we have donor or acceptor impurity in Gallium Arsenide?
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