N-Type & P-Type Structures: Electron Flow

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In summary, when doping an impurity onto a pure intrinsic silicon crystalline structure, one more free electron is added to the N type, making it more resistant to electron flow from a power source with a potential difference. Similarly, the P type becomes more conductive due to the creation of a hole when doping. However, if the concentration of free carriers becomes too high, there may be an increase in resistance due to scattering. Additionally, near a p-n junction, the recombination of free electrons and holes creates a depleted region that produces a potential gap for further transport of charge carriers.
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Windex
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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 arsenic atom make the ntype more resistant to electron flow from a power source with an emf/voltage/potential difference?

I also wonder about the vice versa for the P-type.

Wouldn't the P-Type be more conductive unlike the N-Type which i am assuming to be resistive?

Mainly because when doping something onto a silicon structure to make it a N-Type a hole is created. Thus allowing electrons to want to take that hole for transportational use.
 
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  • #2
Windex said:
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 arsenic atom make the ntype more resistant to electron flow from a power source with an emf/voltage/potential difference?

I also wonder about the vice versa for the P-type.

Wouldn't the P-Type be more conductive unlike the N-Type which i am assuming to be resistive?

Mainly because when doping something onto a silicon structure to make it a N-Type a hole is created. Thus allowing electrons to want to take that hole for transportational use.

Well, I do not quite understand what your problem is.

When you add impurity atoms to the silicon, they are built into the crystal, they just occupy the place of Si atoms. The crystal stays neutral, but acquires loosely bound electrons when the impurity is a donor with higher valence than Si. These loose electrons are exited at relatively low temperatures already. They leave their parent atoms, and can migrate freely in the crystal.
On a similar way, introduction of a 3-valence impurity (acceptor) means a missing electron from a bond: this empty place can migrate around in the crystal and we call this empty place "hole".
Conductivity increases when the number of free carriers increase in the crystal. If the concentration of the free carriers is very high there can be an opposite effect because of scattering among each other. This effect would increase the resistance.
If there are both acceptors and donors in a region, as it is near a p-n junction the free electrons and free holes would "recombine" making a "depleted region" near the junction, which is free from charge carriers, but having static charge distribution. This charge distribution produces a potential gap for further transport of electrons to the p type side and holes to the n type side across the junction.

Was it that you wanted to ask?


ehild
 
  • #3


You are correct in your understanding of how doping an impurity onto a pure intrinsic silicon crystalline structure creates an N-type semiconductor. The addition of an extra electron from the impurity atom makes the N-type structure more resistant to electron flow from a power source. This is because the extra electron is bound to the impurity atom and is not able to move freely throughout the structure. This creates a barrier for electron flow, making the N-type structure more resistive.

On the other hand, doping an impurity onto a pure intrinsic silicon crystalline structure to create a P-type semiconductor results in the creation of a hole. This hole acts as a positively charged particle and is able to attract and accept electrons from neighboring atoms. This makes the P-type structure more conductive as there is a higher concentration of mobile charge carriers (electrons and holes) that can move throughout the structure.

In summary, the N-type structure is more resistive due to the presence of an extra electron from the impurity atom, while the P-type structure is more conductive due to the presence of holes. Both structures have their own unique properties and are important in the functioning of electronic devices.
 

1. What is the difference between N-type and P-type structures?

N-type and P-type structures are two types of semiconductors used in electronic devices. The main difference between the two is the type of dopant used. N-type structures are doped with elements such as phosphorus or arsenic, which have extra electrons, while P-type structures are doped with elements such as boron or indium, which have fewer electrons.

2. How does electron flow differ in N-type and P-type structures?

In N-type structures, the extra electrons from the dopant are free to move throughout the material, creating a surplus of negative charge. This allows for easy flow of electrons or current. In P-type structures, the dopant elements create "holes" or spaces in the material where electrons are missing. These holes can move through the material, creating a surplus of positive charge and allowing for current flow.

3. How do N-type and P-type structures work together in electronic devices?

N-type and P-type structures are often used together in electronic devices to create a junction or barrier between them. This junction creates a potential energy difference that allows for the controlled flow of electrons from the N-type side to the P-type side. This is the basis for many electronic components such as diodes and transistors.

4. What is the role of impurities in N-type and P-type structures?

Impurities, or dopants, are essential in creating N-type and P-type structures. By adding dopants, the number of electrons and holes in the material can be controlled, allowing for the desired type of conductivity. Without these impurities, the material would have either too many or too few electrons to function as a semiconductor.

5. How do N-type and P-type structures affect the efficiency of electronic devices?

The use of N-type and P-type structures allows for the controlled flow of electrons, making electronic devices more efficient. By creating a junction between the two types of structures, current can be easily controlled and manipulated, allowing for the creation of complex electronic circuits. N-type and P-type structures also have different properties that make them suitable for different types of electronic components, further increasing efficiency.

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