Semiconductor Definition and 347 Threads

Homework Statement This isn't a problem as such. This is about a practical I did, to verify the non-classical model of silicon conductivity (which increases with temperature) and then to calculate the band gap energy of silicon. Homework Equations This was the main equation of the model...

I'm wondering what determines Si indirect semiconductor? Si is cubic diamond structure. So it's optically and electrically isotropic (1st&2nd rank tensor properties). And why is GaAs direct semiconducto even though its crystal structer and chemical bonding is so simliar to Si? Isn't it crystal...

i am not able to understand this line.. in semiconductor laser the transition probablity for a radiative transition across the conduction and valence gap must be high and must exceed the probablity for non -radiative transfer of energy to the lattice. please explain this theory.

Here's a story about a new proposal from Prof T P Ma, called Unipolar CMOS: http://www.semiconductor.net/article/CA6602780.html?desc=topstory This may take the P out of P-N semiconductors, boosting performance by 3 to 20 times, depending upon the material.

hi which expermient we should do to proof that a material's semiconductor?? thanks for replying

Can a semiconductor absorb a higher energy photon than its Band gap Eg and make a transition from valence band to conduction band? For a example commonly used IR detector is InAs (semiconductor) whose Eg is 0.354 eV, if a blue light falls on it, will it able to absorve that energy and make a...

In the first diagram on http://hyperphysics.phy-astr.gsu.edu/hbase/solids/fermi.html" , the band gap in a semiconductor is shown. What is the corresponding Fermi momentum? If you plug E_F into the dispersion relation, you get no solution for k_F, right? I ask because an equation is given...

I've been doing some practice semicon. problems and there are a few remaining ones I've been having issues solving. I'll do one at a time Question: What happens when an n-type and p-type material are merged to form a p-n junction? Provide an explanation as to the amount of net current flow in...

Hey everyone, I'm wondering if anyone out there could recommend a great intermediate textbook for studying Semiconductor Physics and Semiconductor Devices (PN junctions, BJTs, etc.). Right now I'm using a textbook by Neaman, which is alright but not great. I've asked people the same...

If you zap a n-type semicond. with a laser with energy at, say, the band gap, what happens to the donor electrons? For sake of argument, let's say we're at low temp. where the occupation of electrons on donors is high. I know technically, you should only get transitions at the energy of the...

Electron concentration in n-type semiconductor Homework Statement At T = 0 K, what is the electron concentration in a Si semiconductor that is doped with Phosphorus atoms at N[SIZE="1"]D=1017 cm^-3? At room temperature, what is the electron concentration of this semiconductor? The electron...

Can anyone give me the link address of following book National Semiconductor Audio/Radio Handbook by Martin Giles

Conductivity of a semiconductor charged with "externally added" electrons Hi, how does it influence the conductivity of a semiconducting sphere (I take a sphere as it should make some considerations easier than for a cylindrical wire) if I add external charges to it? Don't know how this...

http://careers.peopleclick.com/jobposts/Client40_GLDTR/BU1/External/139-27001.htm?ShowReturn=Yes Can someone in the EE or semiconductor field specifically give me more insight into this job position? It's for an internship type job and I was picked to interview for it. Is this something...

There is a doubt i have with the bonding in a P type semiconductor. It is said that for an atom to be stable there are needed 8e's in its valence shell. In the case of a P type semiconductor there are 7. What is the cause behind the trivalent atom forming bonds with the neighbouring...

Hi, I am going to be a TA for the course semiconductor physics. The course is for the 3rd year undergraduate students so it will start from the very beginning concepts of semiconductors. Can you suggest some books containing problems about this field, it would be great if the solutions...

Homework Statement The donor state for tellurium (Te) in GaAs is 5.9 meV below the conduction band (E=E_{c}). At room temperature, what fraction of the states are empty if the Fermi energy lies 0.1 eV below E_{c} Homework Equations E_{c}|_{GaAs}= 1.42eV E_{d}= E_{F}=...

Question: A light-emitting diode (LED) made of the semiconductor GaAsP gives off red light \lambda =650nm. what is the band gap for this semiconductor? I know the E=hc/ \lambda so it means the band gap is 1240/650=1.9 ev ??

can anyone suggest a topic on semiconductor physics that is great for a thesis study? thanks

Can anyone give me some examples of some of the most cutting-edge/futuristic/"we're not there yet" applications for semiconductors? You know... the "exciting" stuff. :biggrin: I'm doing an informal presentation for my solid state class, and wanted to get some ideas of what I should research...

Hi everyone, I don't have any homework question but I need help on a different thing: I have to write a lab report on "Semiconductor Diode" ... so if you guys know any useful website that can give me some useful and important information (such as appliactions of semiconductor diode...

hi guys, i have two semiconductor questions that have been troubling me. 1. can measured carrier lifetimes be used to determine if the material is n-type or p-type? 2. what would be the effect on the lifetime of increasing the sample temperature? i have been getting mixed information...

Two semiconductor materials have different bandgaps, different work functions, electron affinities and dielectric constants. Let's assume they are lattice matched. The larger bandgap material is doped n-type (or N-type) and the smaller doped p-type. In the heterojunction formed epitaxially...

Homework Statement The following is a random experiment. A wafer from a semiconductor manufacturing is to be selected randomly and a location on the wafer inspected for contamination particles. The sample space for the number of contamination particles at the inspected location is S= {0...

For the current-voltage characteristic of a p-n diode which is foward biased: ln i = ln i˚ + eV/2kT where i˚ = a constant current e = electronic charge k = Boltzmann constant T = absolute electron temperature i and v are current and voltage respectively, for which I have a series of...

Semiconductors and isolators are only different in that the energy gap of the former is smaller than 2eV, and of the latter it is larger. I can change the energy gap by doping - but can I make any isolator a semiconducter? What are the limitations?

can anyone explain about high speed semiconductors . how do ge and gaAs can achive those speeds

Hello, i have a revision question that I'm only part-able to answer. The question is: Explain why an LED operating at a fixed current would be more stable than one operating at a fixed voltage.Consider the effect of the device heating on the IV characteristics.Explain under which condition...

REU for EE major that wants to get into applied semiconductor physics... hello, I am a dual major in EE and compE, with minors in both chemistry and physics (3 credits away from the chem minor, and I would like to take quantum mechanics, contemporary physics, and solid state physics, which will...

Is a semiconductor with a p-n junction considered a transistor or just a diode? If it is just a diode, are transistors always triodes?

Question: Silicon at T=300k contains acceptor impurity atoms at a density of Na=7*10^15 cm^-3. Determine Ef - Ev. My solution: By using the formula Ef -Ev= KT ln(Nv/Na) fermi energy type I had trouble computing this formula due to not having the value of Nv. So, I would appreciate if...

Hi, Did some one calculate the dispersion characteristics of TM volume modes in layered magnetized semiconductor structure?

hi all, I am new here so if i break any rules please correct me er I am puzzled over an assignment and have no idea how to search for it, the question ask for the elements that was used to make semiconductor componets before it was replaced by silicon.. please help..a site help would do just...

Hi, I'm doing research to chipproduction, and I can't seem to figure out how transistors really work (in detail). I'm looking at this CMOS inverter gate for example: http://people.deas.harvard.edu/~jones/es154/assigns/prob_assign_01/prob_assign_5_01/cmos_1.gif More detailed...

The problem is an experiment has to be set up to investigate how the breakdown voltage (which occurs by a large reverse potential difference is applied to the diode, and the diode then passes a large current) of a semiconductor diode is affected by temperature. My problem is how can I vary...

In terms of the semiconductor Silicon: N types have on more free electron added to its structure from doping an impurity on it. Such as an arsenic impurity onto a pure intrinsic silicon crystalline structure. However wouldn't it having one more electron inside of it that is bound to the...

why is that the fermi level should be constant throught the system under equilibrium conditions? can I know the physical outcome of that condition or the violation of the same?

Hello, my question is the following: we know from books on semiconductor physics that the energy levels of the electrons in a pure semiconductor cristal form in fact bands of energy. I was wondering why these energy levels are in the form of bands an not simple distinct energy levels as...

by Joao Magueijo This is a very readable book which I would recommend to students of physics in general. The first half of the book is devoted to a rather good explanation of the current understanding of the speed of light, Special and General Relativity. His explanations compete with any...

i hope to know the def. and the properties of magnetic semiconductor :confused:

i have a basic question about IC we give 5 volt in general into an IC but the size of the IC is in nano measure if this 5 volt is given to such a small area the volt/area will become very large and how the IC still functions without burning. let me know how this happens .

Hey guys, this is my first time posting here (so if there's already a thread about lasers, please direct me there) Does anyone know a good source for the theory of lasers (specifically semiconductor lasers) at a second year undergrad level? I've looked at a number of books including Laser...

Hand-to-Hand Model for Tropomyosin Fast Diffusion. Semiconductor Mechanism for Diffusion of Tightly-Binding Proteins: http://actomyosin.narod.ru/h2h-model.htm Would you be so kind as to recommend me some expert who could be interested in view a possible semiconductor mechanism for...

Does an n-type semiconductor exhibit a negitive charge, or is it electrically neutral? Why? I know that a n-type semiconductor is negitive charge thanks joe

Do you all know where and for how much money I can get a large amount of degenerate semiconducting wire? It'll probably be aluminum or copper alloyed with a little iron, but I really don't care what it's made of, as long as it has a huge relaxation time and that I can be quite sure of what that...

ARGH! Bad night! Just a few minutes of inattention. I neglected to remove a rubber/plastic cover from a power meter, the meter was then placed in the beam path of a 7W UV laser, the melting plastic deposited on the nearby lens, toasting the coating, trashing the ~12K$ lens! I don't like making...

1. What is the difference between extrinsic and intrinsic behaviour in a semiconductor? How can you determine what temperature a semiconductor material such as Silicon will revert to intrinsic behaviour, given the donor, intrinsic carrier concentration and the energy gap? - I am thinking that...