WAEC Physics 2016 Theory — Question 6

Model answer

(a) Doping is the process of adding small amounts of suitable impurities to an intrinsic semiconductor. An intrinsic semiconductor is a pure semiconductor. Impurities can either be donors or acceptors and they increase the conductivity of a pure semiconductor. (b) When a pure semiconductor is doped, the relative number of charge carriers (electrons or holes) within the semiconductor increases, and this affects and increases the conductivity of the semiconductor.