Charge carriers Definition and 22 Threads

Suppose I have a perfect crystal(e.g.TiO2-Rutile, band gap=3ev), under UV light, there should photoconductivity, according to the condensed matter theory, some of these excited conduction band electrons would form small polarons, I am wondering how many percent of the free conduction band...

If there is some incoming light that has hit electrons of a N-type doped silicon and broke loose these electrons from their covalent bounds and excited them to the conduction band and also excited the electrons in the donor energy level to the conduction band as well, here we know that, the...

Homework Statement:: Hi, It's been a while since I have reviewed my basic semiconductor physics and I have some doubts. In a P-Type doped semidoncutor material, I understand that Group III elements such as Boron are added to a Group IV element such as Silicon and thus the Boron atom has one...

I am needing clarification for a concept. I understand that electrons carry a negative charge and that protons carry a positive charge. I also understand that a plastic rod picks up electrons when I rub it with a piece of wool. From the conservation of charge, the piece of wool must have a...

I have a simple two-part question, or two simple questions. 1. What is energy? 2. What is charge? The charge I'm referring to is the charge on charged subatomic particles. And atom's charge is defined by the number of electrons and protons present in it. But an electron itself is called a...

For a lab I just finished this past week, we were working with the hall effect and finding hall voltages. The metals used were p-germanium and n-germanium semi-conductors. I understand why in n-germanium the hall voltage is positive and p-germanium is negative assuming negative charge carriers...

Homework Statement You dope an $n$-type substrate at time ##t=0## with electrons and holes around the points: ##\vec{r}_{0,c}## and ##\vec{r}_{0,v}## respectively. The initial densities' distributions are: $$\Delta n (\vec{r},t=0) = \frac{\Delta N_0}{(2\pi...

Hi all, this question comes from an old related thread .. https://www.physicsforums.com/threads/help-in-semiconductors-minority-and-majority-carriers.613598/ I'm also interested in the definition of these 'minority charge carriers' in semiconductors. I don't understand the explanations in the...

Homework Statement The beam of electrons in a cathode ray tube contains electrons traveling at 8.4x106 ms-1 and the current throgh the tube is 2.8 micro A. a) how many electrons are emitted per second from the cathode of the tube b) what is the number of electrons per unit length of the beam...

Homework Statement ABCD is a plane rectangular strip of conducting material of uniform thickness, with a steady current flowing uniformly from AD to BC. The potential difference between E and F, the mid-points respectively of AB and CD, is zero, but when a magnetic field is set up at right...

Unlike BJT, Why the minority charge carriers in FET do not participate in conduction? What is actually happening with the minority charge carriers?

Hello Forum, An electric current is the flow of electric charge: charge in motion. The charges can be electrons, ions, etc. movingi in a solid, liquid, gas. When dealing with semiconductors the concept of hole is introduced. I understand that only the electrons are moving and the constitute...

what happens to the minor charge carriers in p-n junction diode when forward biased?

In solid state physics the "holes" usually regarded as an effective positive charge carriers. In order to have neutral charge some object needs to have an equal amount of protons and electrons. If some material such as an intrinsic semiconductor has equal amount of protons and electrons + some...

Homework Statement It's the third part which I'm stuck on. Homework Equations The Attempt at a Solution I've substituted in all the numbers and, multiplied by the density but I am still not getting the correct answer; where a I going wrong? I got 6.13*(10^11) m^-3 The answer given is...

can someone please provide me with a proof or even just an intuitive explanation

Why is the number of charge carriers per unit volume is inversely proportional to resistance?If there is more charges carrier, it doesn't increase the collision between free electron which causes in increase of resistance?sorry for my unclear concept of Electricity circuit.I hope there will be...

What would happen hypothetically if there was a positive charged particle the same size as an electron (that wasn't antimatter), that carried current in the opposite direction in a wire to a normal conventional current in another wire? According to the Lorentz force they would attract so again...

Hi everyone, I hope this question hasn't be asked and answered already in this forum, I searched through all related threads but I couldn't find an answer specific enough to my question. Consider a simple circuit with a DC battery and resistor. When the electrons (the charge carriers in...

I'm studying Solid State Physics and I have some problems with a problem. It is stated like this: Consider a system of two charge carriers in the Drude model. The two carriers have the same density n and opposite charge (e and-e), and their masses and relaxation times are m1,m2 and r1,r2...

Hi, This is my virgin post. This forum has been a great source of information for the past one year. I am a high school teacher from Singapore. In the study of electrostatics (more specifically induction), we often encounter the scenario below: Two insulated metal spheres touching...

Hello. I'm trying to find the individual contributions of carbon atoms to the charge carriers in graphene. In other words, I'm trying to answer "How many charge carriers does one carbon atom supply?" Here is what I've done so far: Taking the max. carrier density as 10^13 1/cm^2 and the...