Depletion region Definition and 29 Threads

I would like to ask about the behavior of a MOSFET as a capacitor, particularly at the onset of inversion/weak inversion - see Fig 2.6(c) At this stage in Fig 2.6(c), there is positive charge at the gate metal/poly contact, then an insulator oxide and then negative ions (positive holes have...

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...

In a diode, we have N side, P side, and a depletion region, made of positive and negative charged sides. N side and P side of the diodes are neutral charge. In N side there are free electrons. In the positive charged side of the depletion region, there are positively ionized atoms that "lack"...

Hi, Lately I've been reading about a lab exercise in which Planck's constant is estimated using LEDs. Every procedure I've encountered states that the energy of an emitted photon (and by extension the potential across the semiconductor's band gap) is equal to the threshold voltage multiplied by...

In an unbiased p-n junction, how does increase in doping affect the width of Depletion Region? I read somewhere that width decreases as increase in carrier concentration leads to more recombination of majority carriers with oppositely charged ions of their depletion regions leading to a...

I am having some trouble understanding the physics behind the formation of Schottky Barriers. According to the convential theory, the idea is that for an n-type semiconductor the electrons in the conduction band can lower their energy by filling empty states in the metal. This in turns creates a...

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...

why do electric field is zero out side of depletion region?

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...

Here's something I can't get my head around: Take a diode (can be schottky, p-n etc) where the predicted depletion region is larger than the actual thickness of that layer will ever be. What happens? I've seen papers where its assumed that this curtails the built in potential. But it sounds...

Hello every one, Here in below figure we can see an ohmic contact formation between a metal and n-type semiconductor . Here how the N-type semiconductor bands are banded upward ? and what type of depletion charge exists there ?

Hello everyone, Recently I have been studying double layers. As I have studied I have realized that there seem to be a lot of similarities between a double layer and a depletion region in a PN junction. The each form electric fields (and thus have a capacitance) and they each limit (or...

Hi, I have a quick question. When constructing a semiconductor diode, the P-N junction is used to create a depletion region (depleted of mobile majority carriers) which is the active volume of the diode/detector. The region enables an electric current generated from the incomming radiation to...

how does letting the electrons diffuse to the P material/region lead to a "depletion" region in the center where the N and P material meet? please go into detail

Hello everyone, My question is about MOS-capacitor, We know that, If we place +ve gate voltage on p-MOS capacitor holes are repelled from semiconductor-oxide interface leaving behind negative charge due to ionized acceptor ions,This results in a depletion region. Now the question is, If we...

Hi the first step to this is usually described as diffusion of electrons from the n type to the p type. However I have encountered sites and books that state that holes diffuse from p type to n type as well. I am of the opinion that only the electrons diffuse, and that there is no diffusion of...

Hi. I am reading about the pn junction, but I have a question. When the junction is formed the holes in the p-type material close to the junction diffuse across due to the concentration gradient. This leaves the acceptor atoms in the p-type material negatively charged. My question is: when...

Dear, In Zener Diode, In highly Doped diode,the breakdown(Zener breakdown) occurs in small voltage.How? Thanks& Regards, Viswanathan.M

At depletion layer of p region, there more negative ions thus negatively charged region. Likewise at n region, it is positively charged. Then why in equivalent forward bias the diode behave as a battery of .7v with positive at depletion region of the p region where it is negatively charged?

How the depletion region act as capacitor? My view is that there are no charges because if formed of recombination of charges. so, there is no charge... So, how can it act like a capacitor? How the electric field is created in depletion region? It's confusing me a lot ...

Homework Statement The problem is what would be the effect on the width of the depletion region of an unbiased PN junction on the doping levels of the P and N sides Homework Equations This is a conceptual question. There is no equation involved. The Attempt at a Solution Increase...

Hello, I am a bit confused about depletion region in NMOSFET transistor. It says here in my book, that when you increase Uds (drain source) above Ugs(gate source) that the current get higher. Ok, makes sense if nothing, from Ohms law. Simultaneously, the depletion region get smaller in...

Homework Statement a. The densities of electrons and holes required for the Fermi levels in both the p- and n-type Ge to enter the bands. That is, in n-type Ge the Fermi level coincides with the bottom of the conduction band and for p-type Ge the Fermi level coincides with the top of the...

I am studying to become and electrical engineer and am currently taking Electronics I. I am having trouble understanding the change in the depletion region that results from a bias. I understand that at the time of manufacture the free electrons from the n-type semiconductor are attracted to the...

Hello, For simplicity's sake, let's take a np junction. Say we connect the left side (n-pole) to a POSITIVE voltage; this is called a reverse bias, because it will result in a small current from n to p. In other words: electrons will travel from p to n across the junction (and holes will...

Hello all, I am somewhat confused in understanding the depletion region of a p-n junction diode.Everywhere a depletion region is defined as a region near the p-n junction which is devoid of charge carriers.And the formation of this region is said is explain that it is due to the diffusion of...

Regarding the formation of depletion region,it forms because free electrons diffuse into p region from n region. after some recombination of holes, a sufficient potential difference is set up to prevent further diffusion. Now, consider the region to the left side of juction(whole P region...

Hi, Quick question. In a PN junction, the depletion region will shrink with an increase in temperature. Why is that? Is the Fermi energy of the p and n semiconductors a function of temperature? Thanks! Jax