A junction, in the context of rail transport, is a place at which two or more rail routes converge or diverge. This implies a physical connection between the tracks of the two routes (assuming they are of the same gauge), provided by points (US: switches) and signalling. Junctions are important for rail systems, their installation into a rail system can expand route capacity, and have a powerful impact upon on-time performance.
A Relativist's Toolkit (2004) lists the Israel junction conditions as:
##1. [h_{ab}]##
##2. S_{ab}=[K_{ab}]-[K]h_{ab}##
Where ##S_{ab}## is the stress-energy tensor of the shell only, and ##[K_{ab}]## and ##[K]## are ##K_{ab}^--K_{ab}^+## and ##K^--K^+## respectively. My understanding is that...
I am thinking about the reason why we cannot probe the built-in potential across a diode with a voltmeter. Obviously, a diode is not an energy source, so it is impossible for it to show a voltage reading. After doing some research, I found some explanations and some questions about them.
1. The...
Hello there,
I am given a diagram of a Josephson Junction like so:
With a magnetic field ##B = \mu_oH## in the z-direction. I'm reasonably sure ##d_x,d_y,d_z## are normal lengths, not infinitesimal lengths although that is up for debate. Using the above equations I rearrange the expression...
For a normal PN junction I would try to find $V_{bi}$ by integrating the carrier density (eg. the electrons n) from one region to the other:
$$\int_{n_{p0}}^{n} \frac {dn}{n} = \frac {q}{kT}\int_{V_p}^{V_n} dV$$
Which would yield:
$$V_{bi}=V_n-V_p=\frac...
Consider a PN junction doped with say phosphorous on the N side, and Boron on the P side. Initially, there is an opportunity for the electrons just below the N conduction band to drop to the lower available energy states just above the P valence band. This leaves the N side positively charged...
(USA) building codes require that wires that are spliced together must be contained in electrical boxes that are accessible - e.g. you can't splice together wires in an attic. So one often finds electrical boxes for ceiling fans or electrical outlets also serving as junction boxes in the sense...
I'm supposed to solve this using nodal analysis. No biggie! I'm just not sure how to handle ia. I've never seen a current indicated in a junction crossing. I searched the web and my textbook and found zilch. I asked a GSI and was informed it is indeed written where is supposed to be. Within the...
I know tight junctions between adjacent cells are very strong and the gaps are practically zero. But what types of chemical bonds are they? Are they covalent bonds or hydrogen or ionic bonds? I mean between the claudin and occludin proteins.
Unbiased circuit (no driving voltage source) **************
Fig 1
The N-type material has a tendency to donate electrons to the P-type (i.e. absorb holes from) across the PN junction via diffusion current exclusively within the conduction band of both materials. It does so after those...
Hi,
Is there a liquid/liquid junction potential between two liquids of same composition but different concentrations WHEN there is no external electrical circuit and then NO electrodes? (Of course this potential is not measurable).
Thanks,
My question for now is as follows: Why does a high doping concentration causes a decrease in the thickness of depletion region.
Any help will be highly appreciated!
Thanks a bunch
Regards!
I've already found the turning points, in the case of the left turning point, the local minimum of the potential, ##\delta_{min}=1.11977## when evaluating for an arbitrary value of current ##J=0.9I_C##. The left turning point is therefore ##\delta_r=2.48243##.
I know the Bohr-Sommerfeld...
I'm new to semiconductors.
While I was studying types of biasing in semiconductors, here's what I read -
'In forward biasing, the width of the depletion region is reduced.'
Here's what I thought -
Since the potential barrier is reduced in the junction due to external potential, the diffusion...
In the paper here, it says no matter what the waveguide structure is, if the smaller waveguide has a TM mode and the larger has a TE mode, then the coupling (Inner cross product \int\int_{S_{smaller-waveguide}} (E^{small}_{transverse} \times H^{large}_{transverse}) . \hat z dS, where z is the...
Everything is okay besides the current gain of this circuit, which is "g" there
The formula of current gain is I_out/I_in
If I call the current flows to R_e I_2, according to KCL, the following formula must be satisfied.
I_in + (β+1)I_b = I_2
Therefore, to know I_in, we should use the...
I have been asked to draft a (informal) research proposal for a PhD thesis. I have some background in quantum information and my interests are leaning towards the AdS/CFT correspondence. I was wondering if you could suggest a few (preferably recent) theory papers at the junction of quantum...
This is the given schematic. The result should be $$A_u = \frac{R_b g_{21}}{1 + R_b g_{22}} = -50$$ and the way I wanted to tackle this problem is by stating $$A_u = \frac{-R_b i_2}{u_1} = \frac{-R_b (g_{21} u_1 + g_{22} u_2)}{u_1} = \frac{-R_b (g_{21} u_1 + g_{22} u_2)}{g_{11} u_1 + g_{12} u_2}...
Homework Statement
A p type semiconductor is brought into contact with an n type semiconductor to form p - n junction. Which statement is false?
A. During forward bias condition, if applied p.d. overcomes the junction potential, electron will cross steadily from n - type side to p - type side...
Homework Statement
Please help me answer thew question in the image.[/B]
Homework Equations
Current Density J=conductivity X Electric field[/B]
The Attempt at a Solution
As the current density depends on the conductivity of the material through which the electrons constitutuing it are...
Hello guys, I stumbled upon this problem while studying non uniformly distributed pn junctions and finding difficulty solving this. Any help will be greatly appreciated.
A diffused silicon p-n junction has a linearly graded junction on the p side with a = 2 x10^19 cm-4, and a uniform doping of...
For my understanding there should be no big difference in i-v curve between regular p-n junction and p-i-n junction, the only difference i can think about is do to the bigger resistance of the intrinsic layer. The curve should look the same only the current will rise little bit slower, because...
If two batteries are connected such that positive terminal of one is in contact with negative terminal of other then we add the potentials so the potential will then be their sum.
Similarly if a battery is connected to a pn junction diode such that positive terminal is connected to negative...
In Vol III, 14-4 and 14-5 of the Feynman Lectures (http://www.feynmanlectures.caltech.edu/III_14.html), Feynman gives a discussion of the p-n junction, in which he derives the diode characteristic equation via a nice, simple and convincing application of the Boltzmann distribution to the...
Often a band diagram is used to explain what happens when two pieces of the same semiconductor, one p-doped, one n-doped, are put together. I am a little confused about it, so here is my question.
Initially and at ##0\mathrm{K}##, the surplus carriers should be confined to their respective...
Hi,how is the movement of the electrons in photovoltaic?
I understand that there is n and p layer. What I do not understand is why the electrons does not move more directly to the p-side from the n-side. In the currect explanation it requires a circuitry.
Thanx.
Hey guys,
Currently taking a semiconductor device fundamentals course and we are learning about R-G currents in the depletion region of a PN junction. Usually we just consider R-G centers as impurities to be avoided in the operation of a standard rectifying diode. However, I was curious as to...
Homework Statement
In an abrupt p-n junction we consider the junction between one side p-doped with ##N_A## acceptor atoms and another side n-doped with ##N_D## donor atoms. Initially the chemical potential is different in the two sides, but thermal equilibrium requires that the chemical...
Homework Statement
A furnace is constructed with 0.5 m of fire brick, 0.15 m of insulating brick and 0.25 m of ordinary building brick. The inside surface-temperature is 1530K and the outside surface temperature is 525K. The thermal conductivities of the fire, insulating and building bricks are...
Homework Statement
I'm doing a course in solid state electronics and we just started PN junctions etc. I'm a bit confused.
So here is what I know so far:
Initially the P and N regions are separated by a a PN junction. At 300K as the acceptor atoms on the P side and donor atoms on the N side...
Hi. So we have all seen the band diagram of a PN junction. In order for the fermi level to be the same on both sides, the P bands are shifted up or the N bands are shifted down. Now that the fermi levels are equal, what would happen if you bent the diode into a ring (annulus) shape? How would...
Homework Statement
find the voltage between a and d and terminal of each batteries
Homework Equations
Junction Rule and Loop Rule
The Attempt at a Solution
I got three equation
JR : I3 = I1+I2
LR :
45-I3-47I3-34I1 = 0
45-I3-47I3+85-I2-18I2 = 0
I can't solve these...
Homework Statement
The thermal conductivity of copper is 4 times that of brass.Two rods of copper and brass having same length and cross section are joined end to end. The free end of copper is at 0 degree C and the free end of brass is at 100 degree C. The temperature at the junction is...
Once the zener Diode is formed by breakdown of pn junction Diode, potential across Diode remains constant. If we again change the configurations from reverse bias to forward bias, is it possible to get back the normal pn junction as before the breakdown and will potential across junction be...
hi, I am looking a derivation of built in voltage, but the only thing I could find is a statement: built in voltage can be derived from band diagram with the Fermi energy constant throughout the device, or from equating the drift current through the junction equal to the diffusion current. I...
Hi. I'm trying to understand how the current in a PN junction depends on various parameters. I have found this formula in Ashcroft and Mermin. It looks like the current will increase if we decrease the density of donors and/or acceptors, Na and Nd. Is this correct?
Hi!
When dealing with a pn homojunction, it is easy to see the features it has at equilibrium, and also the features it has with forward/reverse bias. Plots show the constant Fermi level at equilibrium and the different Fermi levels for a forward bias; moreover, examples show how much the bands...
Homework Statement
based on this picture in the notes , the author gave that if D is below B , then h2 and Q2 = 0 , what dos it mean ? what does it mean ? water cannot flow out and in from B ?
please ignore the pencil sketched-part
Homework EquationsThe Attempt at a Solution
Hello!
The (potential) energy of an electron in a solid structure is always negative; also the E_c and E_v levels (conduction band and valence band limits) are negative, in the band diagram of a pn junction.
When the junction is built and thermal equilibrium is reached, the depletion region...
Hello!
Some of the processes caused by a pn junction are not clear for me. Just after the contact between the p and the n region, a migration of charges happens in a semiconductor junction in order to reach an equilibrium condition. A valence band and a conduction band are present in both...
Homework Statement
T junction
5 kg/s of methane enters on one side at P1 = 1 MPa, T1 = 400 K,
and 1kg/s of methane enters on the otheras a saturated liquid at P2 = 1 MPa.
The two streams are mixed and emerge at P3 = 1 MPa.
Determine the temperature of the discharge stream (T3).Homework...
Hello,
I am curious as to how one appropriately matches an interior and exterior solution in GR, i.e. where the interior corresponds to the field of some finite spherical mass (perfect fluid sphere, for the Schwarzschild interior solution). Specifically, looking at both the Schwarzschild...
Hello.
I've learned that in PN junction, forward-biasing on it pushes holes in P-type and electrons in N-type toward the junction so depletion width is reduced. Is it due to that in N-type side(P-type side), pushed electrons (holes) are recombined with holes (electrons) in depletion zone?
And...
Hello.
I've learned that in PN junction, forward-biasing pushes holes in P-type and electrons in N-type forward junctions so depletion width is reduced. Is it due to that in N-type (P-type), pushed electrons (holes) are recombined with holes (electrons) in depletion zone?
And what is true...
Homework Statement
In my lab today, I created a circuit with resistor (R1) in series with a set of resistors in parallel (R2//R3).
Using an ammeter, I measured:
I1 = 2.30mA
I2 = 1.25mA
I3 = 0.38mA
Homework Equations
Junction Rule: ΣI = 0
The Attempt at a Solution
So applying the Junction...
I understand why the potential difference across the pn junction decrease in case of the open circuit, but why does it decrease in the short circuit,
And why in the J-V equation we use V = Voc ( where qVoc is the energy between the quasi fermi levels) and what if the quasi fermi levels aren't...