Intrinsic semiconductor vs Extrinsic semiconductor-difference between Intrinsic semiconductor and Extrinsic semiconductor
This page on Intrinsic semiconductor vs Extrinsic semiconductor describes difference between Intrinsic Semiconductor and Extrinsic Semiconductor.
Semiconductor: It is a small component having an electrical conductivity between high conductivity of metals and low conductivity of insulators. It has resistivity in range of conductors/insulators and has negative temperature coefficient of resistance. The conductivity increases not only with the temperature but is also affected very considerably by presence of impurities in crystal lattice.
Semiconductors are used in wide variety of solid state devices such as transistors, ICs, diodes, photodiodes, LEDs etc. Principal semiconductors include Germanium semiconductors and silicon semiconductors.
Following are the characteristics of a semiconductor:
• It has crystalline structure.
• Its conductivity is greatly affected by light rays of high intensity, ultra-violet rays and infra-red rays.
• Its conductivity varies in accordance to temperature variations.
Semiconductor material in its pure form is known as intrinsic semiconductor.
Semiconductor material added with other element is known as extrinsic semiconductor. For example, N-type and P-type materials.
When a trivalent element(e.g. indium, gallium) is added to tetravalent semiconductor ( germanium or silicon) then a deficit of electron is produced for each impurity atom; such type of material is known as P-type material.
When a pentavalent element (e.g. arsenic, antimony) is added to tetravalent semiconductor, then a surplus electron is produced by each impurity atom; such type of material is known as N-type material.