What is the Difference Between Intrinsic and Extrinsic Semiconductors?

By BYJU'S Exam Prep

Updated on: September 25th, 2023

Difference Between Intrinsic and Extrinsic Semiconductors: A semiconductor is an electrical material that exists between an insulator and a conductor. The most known semiconductors are Si and Ge. Semiconductors are classified into two types: intrinsic semiconductors and extrinsic semiconductors (p-type and n-type). The major difference between Intrinsic and Extrinsic Semiconductors is that in intrinsic semiconductors, a semiconductor is in its purest form whereas it does not happen in extrinsic semiconductors.

The intrinsic semiconductor is pure, whereas the extensive semiconductor contains impurities to make it conductive. At room temperature, intrinsic conductivity is zero, while extrinsic conductivity is quite low. This article presents an overview of intrinsic and extrinsic semiconductors using doping and energy band diagrams along with the difference between intrinsic and extrinsic semiconductors.

Download Electronic Devices Formula Notes PDF

Difference Between Intrinsic and Extrinsic Semiconductors

We have provided the difference between intrinsic and extrinsic semiconductors listed in the table below.

Key Differences Between Intrinsic and Extrinsic Semiconductors

Intrinsic Semiconductors Extrinsic Semiconductors
Semiconductor in its purest form.       Semiconductor in its impure form. 
It has low conductivity. It has a higher conductivity than an intrinsic semiconductor.
The band gap between the conduction and valence bands is quite narrow. The energy gap is greater than that of an intrinsic semiconductor.
Fermi level can be found in the forbidden energy gap. The presence of a Fermi level depends on the type of extrinsic semiconductor.
Temperature alone determines electrical conductivity. Electrical conductivity in a pure semiconductor is affected by temperature as well as the quantity of impurity doping.
Pure Silicon and Germanium crystalline forms are examples. Impurities such as As, Sb, P, In, Bi, Al, and others are doped with Germanium and Silicon atoms.

What is an Intrinsic Semiconductor?

An intrinsic semiconductor is made from an extremely pure semiconductor material, thus they are often referred to as pure semiconductors. These are fundamentally undoped semiconductors with no doped impurities. Intrinsic semiconductors have essentially no conductivity at ambient temperature. Because no other element is present in its crystalline form. 

Intrinsic semiconductors have essentially no conductivity at ambient temperature. Because no other element is present in its crystalline form. The periodic table’s group IV elements combine to generate an inherent semiconductor. However, silicon and germanium are the most commonly used materials. This is because, in their instance, only a minimal amount of energy is required to break the covalent bond.

What is an Extrinsic Semiconductor?

Extrinsic semiconductors are those that have had an impurity supplied to them at a controlled rate in order to make them conductive. While insulating materials can be doped to form semiconductors, intrinsic semiconductors can also be doped to form extrinsic semiconductors. These are naturally extremely conductive. Extrinsic semiconductors, on the other hand, are of two types: p-type and n-type semiconductors.

It is worth noting that the type of element doped to the pure semiconductor determines the categorization of the extrinsic semiconductor. By inserting group III elements or trivalent impurities into pure semiconductors, p-type semiconductors are created. Because a trivalent impurity contains just three electrons in its valence shell, it is also known as an acceptor impurity. The addition of group V elements or pentavalent impurities to a clean semiconductor produces n-type semiconductors. Because a pentavalent impurity has 5 electrons in its valence shell, these are known as donor impurities.

Check out some important topics related to the difference between Intrinsic and Extrinsic Semiconductors in the table provided below:

Difference between C++ and python Difference Between Calloc () and Malloc ()
Difference between electric potential and potential difference Difference Between Greedy Method and Dynamic Programming
Difference between C and C++ Difference between rational and irrational numbers
Our Apps Playstore
SSC and Bank
Other Exams
GradeStack Learning Pvt. Ltd.Windsor IT Park, Tower - A, 2nd Floor, Sector 125, Noida, Uttar Pradesh 201303
Home Practice Test Series Premium