Semiconductor Definition and 400 Threads

Homework Statement a) A quantum well contains electrons at a sheet carrier density of n_s =2 \times 10^{16}m^{-2}. The electron effective mass is 0.1m_e^*. Calculate the Fermi energy of the carrier distribution in the well. You may assume the spacings between sub-bands in the quantum well is...

Homework Statement [/B] (a) Explain the terms intrinsic, extrinsic, mobility and effective mass in semiconductors (b) What is a hole and explain its mass and charge (c) Why is mobility of holes often less than mobility of electrons? Find the number density of holes and electrons (d) Find the...

Hi guys, there are a lot of textbooks and articles describe the electric field in depletion region at thermal equilibium, but very few of them tell what happens to the field under bias. I am wondering if the electric field in the depletion region simply changes linearly with reverse bias? Or if...

Homework Statement Determine values for beta the constant of proportionality for a semiconductor. Homework Equations Given below. The Attempt at a Solution Im struggling with line 2 to line 3 of the solution. The problem I'm having is I can't see where the squared exponential term has...

Homework Statement we look at a silicum n++ p+ n transistor. given: NE= 1,0×1018 cm–3; NB= 2,0×1016 cm–3; NC = 2,0×1015 cm–3; here E stands for the emitter, B for the basis and C for the collectorHomework Equations a. calculate the distance in eV from the fermi-level to EFi for the emitter...

Taken from my textbook: My understanding is that: One valence electron, 2 spin states -> Half-filled Brillouin zone Seeking inspiration from "Nearly Free Electron Model": gaps open up at zone boundaries States nearer to zone boundaries get pushed down in energy further Since a fermi...

I have calculated the electron transmission function T(E) over a potential step of height V0 using T-matrices. I model a semiconductor heterojunction, which requires different effective electron masses on either side of the step. The wave functions on either side of the step are planar waves...

From some literature, I read the following band structure of the Al doped Si. The explanation offered: "have vacant acceptor levels at energy Ea above the valence band. Electrons from the top of the valence band can be easily excited into these levels." I thought the above explanation is...

I have calculated the electron transmission function T(E) over a potential step using T-matrices. I model a semiconductor heterojunction, which requires different effective electron masses on either side of the step. We have 2 boundary conditions at the step at x = x0: Y1(x0) = Y2(x0)...

sorry, really didn't know where to post something like this. But where can i get a hold of a wire of semiconducting material?

i would like to know all the details about the band structure in a semiconductor and in particular what we call : yours sincerly guedman

As the atoms of a material are brought closer together to form the crystal lattice structure, there is an interaction between atoms, which will result in the electrons of a particular shell of an atom having slightly different energy levels from electrons in the same orbit of an adjoining atom...

What are the commonly asked questions for the semiconductor process engineer position ? I am assuming cleanroom equipment working principles.. what else? Thanks in advance for your responses.

Hello everyone, I have a quick question about the energy of the silicon. I know that, as a semiconductor, the silicon has an energy gap between the valence band and the conduction band. But according to this image ...

Hello. I'm currently taking a physics course that gives me the freedom to take any subject related to semiconductors and do some research on it, presenting it at the end of the semester. I know I want to do something related to programming, but I'm having a hard time finding a theme. Hence me...

Why is black phosphorus a semiconductor with a direct bandgap? The problem is mentioned by the two following references: "The three bonds take up all three valence electrons of phosphorus,so, unlike graphene, monolayer black phosphorus is a semiconductor with a predicted direct bandgap of 2 eV...

I'm trying to understand how a diode works and for this I've used(among other resources) the book written by Albert Malvino, Electronic Principles. Everywhere I read about this topic, it says that when the N-type and P-type semiconductors are joined together, the free electrons from the N-type...

For a wavefunction at the Brillouin boundary we have: \langle k|H|k\rangle = \epsilon_0 (\vec k) \langle k'|H|k'\rangle = \epsilon_0 (\vec k+\vec G) \langle k'|H|k\rangle = V_G = \frac{1}{L^3} \int e^{i(\vec k - \vec k') \cdot \vec r} V(r) d\vec r \langle k|H|k'\rangle = V_G^* Using...

I understand the difference between p-type and n-type semiconductors but I just don't understand how adding a p-n junction to a circuit affects it. Can someone please explain how semiconductors work? For example, if I had a circuit with just a battery and a light bulb, what would change if I...

When electrons leave the valence band and jump over the gap to the conduction band, what is the density of the remaining holes? If 2.5 electrons/cm^3 leave the VB to the CB, will the density of remaining holes be 2.5 electrons/cm^3? To me it is logical, but I am wondering if mass of electron...

I was wondering if it would be possible to determine if a Schottky diode was n-type of p-type (in the bulk) by only using I-V measurements?

I was wondering if it would be possible to determine if a Schottky diode was n-type of p-type (in the bulk) by only using I-V measurements?

I've been playing around with some ideas of electron-hole pairs in semiconductors lately, have realized that I'm confused about some basic conventions that maybe the physics forum community could help clear up. Let's imagine that we have a direct gap semiconductor initially at zero temperature...

What is a purpose of a substrate in an electronic device? In particular semiconductor lasers, why is it made of semiconductor? Thank you.

http://physics.stackexchange.com/questions/156708/can-the-relative-permittivity-of-a-semiconductor-material-be-lower-than-1 To measure the relative permittivity of a p-type semiconductor material (a metal phthalocyanine ) , a M-S-M structure was made by thermal evaporation method. The...

Is there a way to fabricate semiconductors thigh common materials at home?

Given a material sample, what are the different experiments that one can perform on it to check if it's a conductor or a semiconductor. For eg, we can measure R at different temperatures. Anything else we can do?

How conductivity increases in n type semiconductor as ni^2 (formula nh multiplied by ne=ni^2 where nh=number of holes per unit volume and ne=number of free electrons per unit volume and ni=number of intrinsic charge carrier per unit volume remain constant?What is the use of increased number of...

I plotted n type carrier density vs temperature plot at zero applied bias and the intrinsic carriers dominate the extrinsic carriers at high temperature, now I wonder how plot changes if I apply positive bias to this semiconductor. Does intrinsic carriers dominate the others at lower temperature?

Hi Guys, i need your help, where can i download free articles about the band gap of semiconductor materials (like copper (II) oxide). don't mention sciencedirect and arxiv, because i already explore that, and they provide limited research articles. thank you.

What exactly is conduction band?electrons from valence band jump into conduction band where they exactly go ,do they go to higher shell or subshell or orbital or stays in same place with more kinetic energy?

I'm very new to semiconductors. I want to do basic calculations. How would I go about calculating and graphing the energy of the electrons and holes given the magnetic field and the state. Also, how would I do the same for the electron and hole population.

I'm looking to buy a semiconductor cross reference book, for part numbers and diode and transistor parameters, including new smt parts. I had an old sgs Thomson book but it got lost in a move, if anyone could recommend me one that would be great. I don't want a link to a website cross...

I've been doing a bit of reading on bandgaps of semiconductors and alloys of semiconductors. I was curious to know is the bandgap of a material, say Silicon, determined or calculated experimentally? How do scientists usually determine this in the lab?

Homework Statement Homework Equations Shown in question. The Attempt at a Solution So I was given this question for homework and I'm really not sure where to start. I'm not looking for somebody to do my homework for me, just somebody to point me in the right direction. The...

I have joined a research lab on semiconductor nano devices and have been recommended to study the Robert F. Pierret book "Fundamentals of Semiconductor Devices" but unfortunately I could not understand most of the concepts after reading first three chapters. I am a computer science graduate with...

If you research the materials semiconductors are made of you will find things such as aluminum gallium arsenide. How do you determine what the p-type and n-type are made of? Shouldn't there be a structural difference in order to create band gap?

I am getting an opportunity to do PhD in semiconductor devices. The professor is quite active in the field and publishing good research. I have no background in solid state physics. How difficult it could be with a computer science background? Also where should I start once enrolled in a...

Hi Guys, I read that the Fermi level of semiconductor, like germanium, is in-between the completely occupied upper band and conduction band, i.e. right in the gap. Why is that? shouldn't it have beed exactly the highest occupied level ?

Hi all, I have a question and ask for a discussion. Can the pumping current of the semiconductor lasers such as DFB laser and FP-LD, be smaller than zero? Best Regards, Jason.galq

A new type of energy storage described which uses quantum way to store energy. ''Battenice''. http://techon.nikkeibp.co.jp/english/NEWS_EN/20140224/335902/ How exactly new energy levels could form under UV light? What do the mean?

please see attached image for problem if a dopant gives an electron it's an n-type, if a dopant takes an electron it's a p-type. i can't see how to relate the hall coefficient value to the property of being a n-type or p-type semiconductor? any pointers on this would really be...

I'm trying to understand the form of the absorption spectrum of a T=0K intrinsic semiconductor. The valence band/conduction band energy diagram looks like; http://postimg.org/image/wyzvo9lsr/ As E = \frac{\hbar^2 k^2}{2m^*} where m^* denotes the effective mass. The image doesn't...

Homework Statement Estimate the electrical conductivity, at 135°C, of silicon that has been doped with 3 x 1024 per meter cubed of aluminum atoms. Assume values for electron and hole mobilities of 0.03 and 0.007 m2/V-s, respectively. Homework Equations σ=|e|(ne*μe+nh*μh)...

My question is about drift and diffusion current.In a semiconductor diode no "bias" condition diffusion is present and due to transfer of charges due to diffusion depletion region created and then this region has ions which produce electric field which results in drift current due to force the...

Homework Statement The current-voltage characteristic curve of a semiconductor diode as a function of temperature T is given by the equation: ##I = I_0(e^{|e|\Delta V / k_BT}-1)## where e is the base of the natural logarithm. |e| is the charge of an electron k_B is the boltzmann's...

I don't know if I am asking some stupid questions but I can't really move without knowing them. (1) In reverse bias situation electrons attracted towards positive terminal and hole attracted towards negative terminal widen the depletion region .My question is that why can't these hole...

Homework Statement Here is the problem in the book: Here is the solution: What I don't get is why the solution defines the fraction to be ni/(5*1022). Shouldn't it be 2*ni/(5*1022) since we have both donors and acceptors, so there are actually twice the number of atoms. Also...

I'm aware that you "dope" them with phosphorous for n-type and boron for p-type (I'm aware other materials can be used and other dopants are preferred in other situations). My question is exactly how is this done? Temperature, Pressure, Sputtering, etc.A white paper or something of the exact...

The question asks for a pn junction, calculate the total bending through energy at zero bias of the conduction band edge passing from neutral n-type section to the neutral p-type section. Additional info: Band gap of silicon Eg = 1.1 eV Density of states at conduction band (Nc) = 2.8e19...