Physics 2002 JAMB Past Questions - Question 48: Pure silicon can be converted to a p-type material by adding a controlled amount of

Correct Answer

D

Explanation

Pure silicon can be converted into a p-type material by adding a controlled amount of certain elements known as acceptor dopants. The most commonly used acceptor dopant in silicon is boron (B). When boron atoms are introduced into the silicon crystal lattice during the manufacturing process, they create "holes" in the crystal structure, which are essentially places where an electron is missing. These holes act as positive charge carriers or "electron deficiencies," and they are responsible for giving silicon a p-type behavior.

The controlled amount of boron added is typically in the range of parts per million (ppm) to a few percent, depending on the desired electrical properties of the p-type silicon material. This controlled doping process introduces just enough boron atoms to achieve the desired level of p-type conductivity while maintaining the overall crystalline structure of silicon. The specific doping concentration will vary depending on the application and requirements of the semiconductor device being fabricated.