Conductivity is a measure of how easily a material allows electric current to flow through it. In semiconductors, conductivity is important because it determines how well the material can be used for electronic devices such as transistors and diodes.
The conductivity of a semiconductor can be measured using a four-point probe technique, where four probes are placed on the surface of the material and a voltage is applied. The resulting current is then measured to determine the conductivity.
The conductivity of a semiconductor can be affected by factors such as temperature, impurities, and the concentration of free charge carriers (electrons and holes) in the material.
The band gap of a semiconductor is the energy difference between the highest occupied energy level (valence band) and the lowest unoccupied energy level (conduction band). A larger band gap means that the material is less conductive, as there are fewer free charge carriers available to carry current.
Yes, the conductivity of a semiconductor can be changed by altering the material's properties, such as temperature, impurity levels, and the application of external electric fields. This allows for the control and manipulation of electronic devices made from semiconductors.