Difference between Intrinsic and Extrinsic Semiconductor

This article covers the key differences between intrinsic and extrinsic semiconductor materials on the basis of purity, conductivity, uses, energy gap, temperature, and examples.

An intrinsic semiconductor is the one which is made of the extremely pure semiconductor material. They have the equal number of holes and electrons so do not conduct the current. Extrinsic semiconductors are made out of intrinsic semiconductors by adding some suitable impurity (P-Type or N-Type) in an extremely small amount.

Characteristics Intrinsic semiconductor Extrinsic semiconductor
Purity Pure semiconductor (with an impurity) is considered to have an intrinsic nature. Such semiconductors are made by adding impurities to pure semiconductors.
Conductivity Low High
Use They are not practically used They are practically used in various applications.
Energy gap  Energy gap is small. The energy gap is more than that in an intrinsic semiconductor.
Electrons Vs Holes Number of electrons and holes are equal. In N-type, electrons are in majority whereas in P-Type, holes are in majority.
Examples Silicon, Germanium For P-Type: Gallium, Aluminum, Boron

For N-Type: Phosphorous, Antimony, Arsenic

Elements table Group IV elements lie in this category. Group III and V elements (as an impurity) are introduced in Group IV elements.
Conductivity Vs Temperature Conductivity increases as temperature rises. Conductivity mainly depends on the impurity added.