Semiconductor Definition and 400 Threads

Homework Statement [/B] I want to find the minimum resistance ##R_L## so as to maintain ##V_z##(voltage of the zener corresponding to the minimum current ##I_{z_0}##) across the same resistor ##R_L##. Homework Equations ##V_z##(voltage of the zener corresponding to the minimum current...

Hi, I'm studying p-i-n photodiode (PD) at the moment and understand that the photodiode's response will depend on the frequency of the light signal going into it. I am struggling however to understand the concept of bandwidth, and why is it that the photocurrent at the PD decreases with higher...

Both the cz (Czochralski Process), and Float-zone refining of silicon require an inert atmosphere, usually argon. How pure does the argon atmosphere have to be? How high of a vacuum has to be pulled before releasing argon into the tank?

Homework Statement [a) Show that chemical potential in intrinsic semiconductor at T = 0 lies exactly in the middle of the energy gap. At what temperature is the chemical potential equal ##(3/4)(E_c + E_v)##, where ##E_c## and ##E_v## are energies od the bottom of the conduction band and of the...

I’m using an inductive heater to try to melt some 99.85% polycrystalline silicon, as would occur in the Czochralski process, but the silicon workpiece is not melting let alone even getting hot. The silicon workpiece is about the size of a playing dice. It becomes conductive at 200 F and becomes...

Hi, I have some chemical abbreviation which I do not understand. Please can you tell me what those abbreviations mean? 1. u-GaN 800nm (C:2E16 at/cm3) (I do not understand what "u" stands for; GaN is Gallium Nitride, 800 nm is thickness of layer, C is concentration of atoms per cm3 but I am not...

Homework Statement Long and thin sample of silicon is stationary illuminated with an intensive optical source which can be described by a generation function ##G(x)=\sum_{m=-\infty}^\infty Kδ(x-ma)## (Dirac comb function). Setting is room temperature and ##L_p## and ##D_p## are given. Find the...

Homework Statement My question is more about understanding the task itself, not about calculation. I am supposed to use the poisson equation, to derive the potential inside a semiconductor for a barrier with potential height ##\phi_B## and a donator doping with ##N1 > N2##. Then I should use...

Hi friends, I'm a brazilian Electronics Engineering undergrad student, going to graduate in 3 semesters. I'm also in the first semester of my Masters in Atomic and Molecular Physics, focused on ab initio simulation of semiconductor crystals (VASP). My main interest is to work in industry in...

I’m using a zvs inductive heater to try to melt some 99.85% polycrystalline silicon, as would occur in the Czochralski process, but the silicon workpiece is not melting let alone even getting hot. The silicon workpiece is about the size of a playing dice, and becomes fully conductive after...

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...

Hi there, it is commonly accepted that the lifespan of crystalline silicon solar cells is about 20-30years. And they define the lifespan as when the solar cells efficiency drop to about lower than 10%. However, what are the possible reasons for the degradation? I can only find research papers...

Homework Statement A novel semiconductor detector crystal requires an average energy of 1.8 eV to create an electron-hole pair, it has a Fano factor of F=0.2. Use this information to calculate the potential resolution for detecting a gamma-ray with an energy of 700 keV. Homework Equations...

Hello guys, I received an admit to grad school for Mechanical Engineering, where my focus was initially Thermo-Fluids . I've also enquired about the Material Science department at the University(in the USA), and they are willing to let me transfer to the Material Science department provided I...

I have a semiconductor substrate and a metal. The metal is coated on substrate then a voltage applied. how can i simulate this in Comsol software.

If a diode is connected with P junction with higher voltage and N with low voltage then why is there a potential rise as opposed to the decrease in potential like in battery?

When a P-N junction is in reverse bias, the drift velocity of the system increases, so why is there no current flow? Is the drift velocity not connected to the current? Thanks in advance.

Hey friends, taking a class on semiconductor fabrication and my professor both can't teach and doesn't use a textbook. I'm going to take it upon myself to learn the material independently, so can anyone recommend a good textbook on the subject? Thanks in advance!

I've been doing some research lately and was wondering what degree is good for the semiconductor industry? Chemical Engineering, Electrical Engineering, or Material Science?

Homework Statement Which one of the following describes the result of doping in semiconductors? a. The impurity provudes additional energy states within the conduction band b. More electron - hole pairs are introduced as a result of doping c. For n - type semiconductor, the number of "holes" in...

Does anyone know of a good resource for semiconductor physics? I can't find much for it and the textbook isn't much help. Here is a https://filebin.net/8navybb1hnt50wi9/Formulae_2017.pdfandhttps://filebin.net/8navybb1hnt50wi9/Formulae_2017.pdfthe textbook is an introduction to semiconductor...

Hey everyone, I'm trying to plot a straight line for a bipolar junction transistor to find the room temperature, T, using my experimental results for the associated base-emitter voltage, ##{V}_{BE}## and collector current, ##I_C##. Here's the equation that I'm using: $$ I_C = α_F {I}_{EO}...

I have a pressing question, but I don't exactly know how best to articulate, or where. I am a wafer fab operator in the semiconductor industry. I usually operate ion implanters. The highest energy ion beams we use are a little over 3.5 MeV. As an aside, I am looking for a way, given that, to...

I have Semiconductor at my home. I had to use a Semiconductor as junction of electrical current. Current at the junction could be so big if I shoot a sun light from lens and mirror to a Semiconductor. What happen about my experiment? What is it a fotoelectric effect?

Homework Statement Consider a circuit that consists on a resistor of an intrinsic semiconductor R and a capacitor C in series. The voltage between the terminals of the circuit is U, which is an alternated sinusoidal voltage. U1, which is the voltage in the capacitor as a phase difference of 30...

Imagine attaching electrodes to a complex sample, e.g. a semi-conductor or a single chemical molecule, leading to some electric current. Can we decompose this electron flow into local flows? - like locally attaching amperometer and counting what fraction of electrons flow directly between given...

Dear members, I am an analog designer and I don't get to do a lot of interesting design work at my job. There is a PhD opportunity that came my way which offers really interesting work (will be in a top tier uni and will be working on project for a world famous research institute). However, I...

Hello I have got a question and i don't know the answer. Please help me. I have a n doped semiconductor. How does the number of conduction electrons depends on temperature and compare the situation to an intrinsic semiconductor? Do i look at the intrinsic density, because when it is n doped...

Homework Statement Homework Equations γ=α+(1/2L)ln(1/Γ1Γ2) where gamma is gain, alpha is absorption constant, and Γ are reflection coefficients. The Attempt at a Solution I'm a little stuck on how to start. If there was no semiconductor gain medium in the cavity then I could just use the...

Homework Statement An intrinsic semiconductor with a direct gap have valance band ##\epsilon_k = E_v-b|k|^2## and conduction band ##\epsilon_k = =E_c+a|k|^2##, with ##E_v=6.0##eV, ##E_c = 5.5eV##, ##a=5.0eV\cdot Å^2##, and ##b=3.0eV\cdot Å^2##. Calculate the chemical potential ##\mu## and the...

in a P-N junction diode, in an equilibrium state, a depletion layer forms in the surface of contact of N type and P type. But the problem is, this layer is formed by diffusion of electron to a lower electron density zone. Why does it always have to form right in the contactt surface? when...

Hi, What are the rules that satisfy which combination of elements are semiconductors? First one is to satisfy the octet rule to form covalent bond. This can be easily checked by looking at the group number, which is indicative of the number of valence atoms. The other is the electronegativity...

From my understanding of semiconductors, we are able to create semiconductors by combining different group of elements that fulfill the octet rule to produce covalent bonds and where their electronegativities provide a energy band gap that is between that of a conductor and insulator. Why is the...

Can you create pure semiconductor quantum dots? I have seen composite ones that are created with elements in the group II-VI and III-V. Moreover, it saids that the size of the quantum dots must smaller than the Bohr Excitron Radius. From my understanding of the Bohr Exciton Radius is the...

Homework Statement A semiconductor has an acceptor concentration of ##6.7 \times 10^{16}##cm##^{-3}##, with no donors. Its intrinsic carrier concentration is ##4.2\times 10^{17}## at 650K. What's the concentration of free electrons at 290K? Estimate the temperature of the crossover between...

Homework Statement A simplified E versus k curve for an electron in the conduction band is given. the value of a is 10 Å. Determine the relative effective mass m* / m0. Homework Equations [/B] m* = ħ2 / (d2E /dk2) m0 = 9.11 E-31kg 3. The Attempt at a Solution The second derivative must...

The depletion layer is formed by the movement of electrons from the n to p side and holes from p to n side of the diode. The layer consists of positively charged donor ions close to the n side and negatively charged acceptor ions close to the p side. When in equilibrium,the barrier potential...

We conducted an experiment in which we found the variation in the resistance of a fairly pure silicon sample between temperatures of about 400K to 600K, and we found a value for the energy gap of silicon of our sample. We were comparing the resistance variation with the model...

Homework Statement This is what the question looks like and I don't even have an idea where to begin since we didn't really cover this during lectures. Homework Equations This is all I have from my notes: also I found that Eg=Ec-Ev Any help appreciated Thanks

I am simulating a system, where I have a semiconductor with a charge distribution in the conduction band coupled to a metal. I want to calculate the electrostatic potential due to this charge distribution but some things are confusing me. To calculate the electrostatic potential I solve Poissons...

In a degenerate n type semiconductor, when the doping concentration has a gradient(say -ve gradient), then how fermi energy level and intrinsic Fermi energy levels will depend upon the concentration gradient? ~If anyone knows anything about it, kindly help.

Suppose I want to solve the 1D, time-independent Schrödinger-equation for a metal-semiconductor junction. In the metal region the Schrödinger equation reads: (p^2/2m + V)ψ = Eψ In the semiconductor region the Schrödinger equation reads: (p^2/2m* + V + ΔESM)ψ = Eψ My question is: Is there a...

Does phonon required a minimum energy in the absorption process of an indirect band gap, and why?

Homework Statement You are given a small slice of doped semiconductor material but you do not know whether it is n-type or p-type Explain with the aid of a diagram the physical principles of an investigation which would enable you to identify the type. 2. The attempt at a solution I searched...

HI guys! I was thinking... What would happen if the atom were considered the smallest thing of the universe, or just that electrons, protons e neutrons were that? That would impact in semiconductors technologies? Or plasma? Or nanotech? How? Thanks in advance.

I was doing an experiment to plot the IV characteristics of a diode. I connected a resistor, diode and milli ammeter in series. I connected a voltmeter across the diode. I measured the diode voltage and diode current. When i changed the resistor, I got a different set of diode voltage readings...

We are doing spectroscopy on some semiconductors covered by a layer of Aluminium. My professor says it might be a challenge for to see the valence band structure of the semiconductor because the metal has a high density of states at the fermi level. Does this make sense to you? Does a metal have...

Hi How to find young's modulus of quantum well semiconductor? For GaAs- young's modulus E=85 GPa and For Al0.3Ga0.7As- young's modulus E=84 GPa. For quantum well Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As Value of young's modulus is?

I'm doing independent study on semiconductors to prepare for a future class and I'm having problems with some problems that concern finding the n and p of doped Silicon given only a temperature, NA, ND, and Ni. I understand that n*p=Ni^2, but, given that this means that n does not equal ND (and...

I am having a hard time understanding flat band voltage in MOS capacitor. Please see the picture below about MOS capacitor. Q0 is a fixed effective charge at the surface between oxide and semiconductor and it is positive here. The voltage across the oxide caused by the fixed charge ψox =...