Semiconductors can be broadly classified into intrinsic and extrinsic semiconductors. The electron in an n type semiconductor is called the majority carrier, whereas the hole in n type semiconductor is termed the minority carrier. Pentavalent impurities such as phosphorus, arsenic, antimony etc are called donor impurity. Such semiconductors are termed as n type semiconductors. Therefore, the fermi level in the p type semiconductor lies close to the valence band. Adding correct impurities can lead to controlled domination of one carrier type. What do you understand by intrinsic semiconductor and. The electrical conductivity of extrinsic semiconductor is large. In n type semiconductor, number of negative charge carriers i. The formation of a pn semiconductor junction is described and its conduction properties are discussed. Intrinsic semiconductor and extrinsic semiconductor. We can define p type and n type semiconductor by their impurities added.
The term p type refers to the positive charge of a hole. Based on the dopants used the extrinsic semiconductors are further classified as ntype semiconductor and p type semiconductor. Sep 23, 2017 apr 07, 2020 n type and p type semiconductors class 12 notes edurev is made by best teachers of class 12. So many people think that p type semiconductor has large number of holes and current conduction is mainly due to these holes. As conduction is due to a large number of holes, the holes in the p type semiconductor are majority carriers and electrons are minority carriers. Are there intrinsic p type or n type semiconductors. The libretexts libraries are powered by mindtouch and are supported by the department of education open textbook pilot project, the uc davis office of the provost, the uc davis library, the california state university affordable learning solutions program, and merlot. Semiconductors are materials which have an intermediate conductivity between conductors and insulators.
As per theory of semiconductor, impure semiconductors are called extrinsic semiconductors. The difference between a ptype semiconductor and ntype semiconductor are given below in tabulated form. The types of doped semiconductors formed after the addition of the impurity are. The semiconductor materials used in electronic devices are doped under precise conditions to control the concentration and regions of p and ntype dopants. Trivalent impurities such as boron b, gallium g, indiumin, aluminiumal etc are called acceptor impurity. In this physics digital electronics video lecture in hindi for class 12 we described different type of semiconductor intrinsic and extrinsic. When the trivalent impurity is added to an intrinsic or pure semiconductor silicon or germanium, then it is said to be an ptype semiconductor. However, unlike intrinsic semiconductor, extrinsic semiconductors are of two types p type and an n type semiconductor it is noteworthy here that the classification of the extrinsic semiconductor depends on the type of element doped to the pure semiconductor. The doping agents used are of two types, resulting in two types of extrinsic semiconductor. This means that for ntype semiconductors, the ionized donor atoms, positive ions, are able to cause an electrostatic attraction with the donated electrons while in ptype semiconductors, the ionized acceptor atoms negative ions cause an electrostatic attraction with the holes created in the lattice. Difference between p type and n type semiconductor.
Conversely, in a ptype semiconductor, holes are majority carriers and. The p type carries a positive charge, while the n type carries a negative charge. Intrinsic and extrinsic semiconductors, fermidirac distribution function, the fermi level and carrier concentrations zeynep dilli, oct. Depending upon the type of impurity atoms added, an extrinsic semiconductor can be classified as ntype or ptype. Semiconductors ppt and pdf report free study mafia. In an extrinsic semiconductor the increase in one type of carrier n or p reduces the concentration of the other through recombination so that the product of the two n and p is a constant at a any given temperature. As opposed to n type semiconductors, p type semiconductors have a larger hole concentration than electron concentration. In n type semiconductor, the population of free electrons is more whereas the population of holes is less.
Depending on the type of doping material used, extrinsic semiconductors can be further subdivided into two classes. An extrinsic semiconductor is a material with impurities introduced. The p type and n type are two different types of semiconductors. Semiconductors types, examples, properties, application. The pentavalent elements are called so as they have 5 electrons in their valence shell. And as it is an extrinsic ntype sc lets say there will be excess electrons in the lattice which on getting sufficient ionisation energy this energy is less than the energy required to jump the forbidden band will get excited to the conduction band. In an ntype semiconductor, number of free electrons n e number of holes n h ptype semiconductor. Difference between n type and p type semiconductor quick.
An extrinsic semiconductor is one in which an impurity with a valency higher or lower than the valency of the pure semi conductoris added, so as to increase the electrical conductivity of the semiconductor. Enee 3, fall 08 supplement ii intrinsic and extrinsic. Apr 10, 2020 n type and p type semiconductors are extrinsic semiconductors to which different impurities have been added, and consequently have different conductive properties. Semiconductor type intrinsic extrinsic ptype ntype. We have already discussed about the concept of semiconductors, their types. Yes, a semiconductor can be intrinsically n or ptype. Extrinsic semiconductor is of two types p type and. N a n 0 n2 i p 0 at equilibrium hole concentration p 0 n2 i n 0. On the other hand, the semiconductors with intentionally added impurities are called extrinsic semiconductors. Extrinsic semiconductors n type and p type semiconductors jeeneet physics wallah alakh pandey. In our article on semiconductors, we discussed that semiconductors are amorphous or crystalline solids that have a conductivity between that of a conductor and an insulator, either due to the presence of an impurity extrinsic semiconductors or because of temperature change. The charges depend on the hole concentration and the electron concentration.
P and n type semiconductor floyd free pdf file sharing. Jul 30, 2017 in this physics digital electronics video lecture in hindi for class 12 we described different type of semiconductor intrinsic and extrinsic. One may think that ntype material has a net negative charge and ptype has a net positive charge. They are mainly classified into two types as follows. Keep in mind that silicon is valence iv four ntype silicon when a silicon atom in the crystal lattice is. One is intrinsic semiconductor and other is an extrinsic semiconductor. The doping of semiconductors the addition of a small percentage of foreign atoms in the regular crystal lattice of silicon or germanium produces dramatic changes in their electrical properties, producing n type and p type semiconductors. Ntype and ptype semiconductors class 12 notes edurev. The pure form of the semiconductor is known as the intrinsic semiconductor and the semiconductor in which intentionally impurities is added for making it conductive is known as. Jul 29, 2017 difference between n type and p type semiconductors.
Intrinsic semiconductor and extrinsic semiconductor the semiconductor is divided into two types. Apr 01, 2019 these impurity atoms are known as dopants. Based on the dopants used the extrinsic semiconductors are further classified as n type semiconductor and p type semiconductor. Firstly, a semiconductor is defined to be extrinsic strictly when we need to dope it with an additional external dopant, i.
The pure form of the semiconductor is known as the intrinsic semiconductor and the semiconductor in which intentionally impurities is added for making it conductive is known as the extrinsic semiconductor. Crystal as a whole is neutral, but the acceptors become an immobile negative ion. Difference between n type and p type semiconductors. Because electrons under ordinary conditions will flow in only one direction through such barriers, pn junctions form the basis for creating electronic rectifiers and switches. A unique feature of the semiconductors is that they are bipolar in nature and in them, the current is transported by the electrons and holes. Semiconductors types, examples, properties, application, uses. It is true that ntype semiconductor has excess of electrons but these extra electrons were supplied by the atoms of donor impurity and each atom of donor impurity is electrically neutral. A ptype semiconductor is created when trivalent elements are used to dope pure semiconductors, like. A single semiconductor crystal can have many p and ntype regions. Group v elements such as phosphorus, antimony and arsenic are usually classified as ntype impurities. Mar 15, 2020 as per theory of semiconductor, impure semiconductors are called extrinsic semiconductors.
The mechanisms of conduction in a metal and in a semiconductor are compared. In ntype semiconductor material, the number of electrons increases, compared to the available number of charge carriers in the intrinsic semiconductor. Depending on the type of doping material used, extrinsic semiconductors can be subdivided into two classes. Intrinsic and extrinsic semiconductors, fermidirac. Ntype semiconductor when pentavalent impurity is added to an intrinsic or pure semiconductor silicon or germanium, then it is said to be an ntype semiconductor. In an ntype semiconductor, the dopant contributes extra electrons, dramatically increasing the conductivity.
The fermi level for p type semiconductor is given as. Apr 07, 2020 ntype and ptype semiconductors class 12 notes edurev is made by best teachers of class 12. Although currents may be induced in pure, or intrinsic, semiconductor crystal due to the. Depending on the type of doping material used,extrinsic semiconductors can be further subdivided into two classes. Difference between p type and n type semiconductors jee. Jun 16, 2017 semiconductors ppt and pdf report free. A p type semiconductor is created when trivalent elements are used to dope pure semiconductors, like. Depending upon the type of impurity atoms added, an extrinsic semiconductor can be classified as n type or p type. In an n type semiconductor, number of free electrons n e number of holes n h p type semiconductor. Pdf thermodynamics of ntype extrinsic semiconductors. Similarly, the n type has a larger electron concentration. The difference between a p type semiconductor and n type semiconductor are given below in tabulated form.
Intrinsic semiconductor and extrinsic semiconductor energy. When a small amount of impurity is added to a pure semiconductor. N type semiconductor 1 n type semiconductor n type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material e. Difference between n type semiconductor and p type. A ntype semiconductor is defined as a type of extrinsic semiconductor doped with a pentavalent impurity element which has five electrons in its valence shell. Where n v is the effective density of states in the valence band.
What is intrinsic semiconductor and extrinsic semiconductor. There will be thermally generated electron hole pairs even in extrinsic semiconductors just like intrinsic semiconductors. Recognize the pn junction under thermal equilibrium. The dopant atoms added to the semiconductor crystal in this case are donor atoms. This document is highly rated by class 12 students and has been viewed 2583 times. Examples of pentavalent impurities are phosphorus or. Depending upon the type of the impurities added, we classify the extrinsic semiconductor in two categories p type and n type. When pentavalent impurity uses for doping then it creates extra electrons in a semiconductor called n type semiconductor or donor. Keep in mind that silicon is valence iv four ntype silicon when a silicon atom in the crystal lattice is replaced with a valence v five atom such as. The extrinsic semiconductor is impure semiconductor. Extrinsic semiconductors technische universitat graz the introduction of impurity atoms that can add electrons or holes is called doping. Therefore, such extrinsic semiconductors are called ntype semiconductors.
Sep 16, 2017 yes, a semiconductor can be intrinsically n or p type. In p type semiconductors, holes are the majority carriers and electrons are the minority carriers. The doping of semiconductors the addition of a small percentage of foreign atoms in the regular crystal lattice of silicon or germanium produces dramatic changes in their electrical properties, producing ntype and ptype semiconductors pentavalent impurities impurity atoms with 5 valence electrons produce ntype semiconductors by contributing extra electrons. P type and n type semiconductor both are extrinsic semiconductors. An extrinsic semiconductor is one that has been doped. Mar 16, 2019 based on the dopants used the extrinsic semiconductors are further classified as ntype semiconductor and p type semiconductor.
We also acknowledge previous national science foundation support under grant numbers 1246120, 1525057, and 14739. Material ntype ptype electron concentration n 0 n d. Difference between intrinsic and extrinsic semiconductors. Ntype semiconductor 1 ntype semiconductor ntype semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material e. A common p type dopant for silicon is boron or gallium. For a doped, or extrinsic, semiconductor, the increase of one type of carriers. A n type semiconductor is defined as a type of extrinsic semiconductor doped with a pentavalent impurity element which has five electrons in its valence shell. Depending on the type of impurity added we have two types of semiconductors. The n type semiconductors are doped with pentavalent impurities. Secondly, despite of the material being pure, the l. As conduction is due to a large number of holes, the holes in the ptype semiconductor are majority carriers and electrons are minority carriers. A barrier forms along the boundary between ptype and ntype semiconductors that is known as a pn junction. The ntype semiconductors are doped with pentavalent impurities.
The doping of semiconductors georgia state university. Apr 30, 2016 in n type semiconductor material, the number of electrons increases, compared to the available number of charge carriers in the intrinsic semiconductor. A semiconductor is usually a crystalline solid in which conductivity due to electron flow is between that of a metal and an insulator. Difference between p type and n type semiconductor p. N type semiconductor when pentavalent impurity is added to an intrinsic or pure semiconductor silicon or germanium, then it is said to be an n type semiconductor. Electrical conductivity of intrinsic semiconductors is poor. However, unlike intrinsic semiconductor, extrinsic semiconductors are of two types ptype and an ntype semiconductor it is noteworthy here that the classification of the extrinsic semiconductor depends on the type of element doped to the pure semiconductor. This process of adding impurities in minute quantities into the pure.
A semiconductor is usually a crystalline solid in which conductivity due to electron flow is between that of a. This relationship is valid for both intrinsic and extrinsic semiconductors. In 100 million parts of semiconductor one part of impurity is added. Based on the type of doping material incorporated, semiconductor crystals are classified into two types particularly ntype semiconductors and ptype semiconductors. It is however the behavior of the pn junction which is the key to the enormous variety of solidstate electronic devices.
Extrinsic semiconductor is formed by adding a small amount of impurity. Extrinsic semiconductors definition, types and properties. An ntype semiconductor is one that has donor dopants deposited. The density of electrons and holes, energy level and fermi level, the direction of movement of majority carriers, etc.
Intrinsic and extrinsic semiconductors, fermidirac distribution function. The semiconductors have the conductivity which is between the conductors and the insulators. Semiconductors in their pure form are referred to as intrinsic semiconductors. The detailed explanation of the two types of the semiconductor is given below. It is remarkable that the modern electronics is based on one type of material, semiconductors. Difference between p type and n type semiconductor circuit. On the other hand, the holes are the minority charge carriers. So, the total electric charge of p type semiconductor is positive. The intrinsic semiconductor is extremely pure semiconductor. Ntype and ptype semiconductors are extrinsic semiconductors to which different impurities have been added, and consequently have different conductive properties. Difference between intrinsic and extrinsic semiconductor.
Extrinsic semiconductors are further classified as. The p type semiconductor has a larger hole concentration, which results in the positive charge. Comprehend an ntype and a ptype extrinsic semiconductor. This means that for n type semiconductors, the ionized donor atoms, positive ions, are able to cause an electrostatic attraction with the donated electrons while in p type semiconductors, the ionized acceptor atoms negative ions cause an electrostatic attraction with the holes created in the lattice. This type of semiconductor is obtained when a pentavalent material like antimony sb is added to pure. Types of doped semiconductors there are two different ways of adding an impurity to the semiconductor atom.
In a ptype semiconductor, the dopant produces extra vacancies or holes, which likewise increase the conductivity. Here p stands for positive and n stands for negative. Conversely, in a p type semiconductor, holes are majority carriers and electrons are minority carriers. Semiconductor materials can be classified into two types viz. Furthermore, taking into account a geometric model developed for n and p type semiconductors in a previous paper, we derive, in the same geometrized framework, the dynamical system on the fibre. An extrinsic semiconductor is one in which an impurity with a valency higher or lower than the valency of the pure semiconductor is added, so as to increase the electrical conductivity of the semiconductor.
The pentavalent impurity or dopant elements are added. Therefore, such extrinsic semiconductors are called n type semiconductors. The number of electron and holes produced due to the thermal energy are equal. Hence in n type semiconductor free electrons are called majority carriers and holes are called minority carriers.