Question

When a pentavalent impurity is added to a pure semiconductor, it becomes:

• A. zero
• B. 10^–2 A
• C. 10 A
• D. 0.025 A

Answer 1

The correct option is D 0.025 A

When a pentavalent impurity is added to a pure semiconductor, it becomes n-type semiconductor. Doping is the process of adding impurities to intrinsic semiconductors to alter their properties. Normally trivalent and pentavalent elements are used to dope silicon and germanium. When an intrinsic semiconductor is doped with trivalent impurity it becomes a p-type semiconductor. The p stands for positive, which means the semiconductor is rich in holes. When we dope intrinsic material with pentavalent impurities we get n-type semiconductor, where n stands for negative. n-type semiconductors have excess electrons in it.