HC Verma Chapter 45 Problem 1

Problem Statement

In a pure semiconductor, the number of conduction electrons is 6e19 per cubic metre. How many holes are there in a sample of 1 cm3?

Key Concepts

Intrinsic semiconductor; electron-hole pairs equal

Relevant Formulas

n_e = n_h in pure semiconductor

Step-by-Step Solution

n_e = n_h = 6e19 m-3 (intrinsic). Volume = 1e-6 m3. Holes = 6e19 x 1e-6 = 6e13.

Final Answer

6e13 holes

Tips and Tricks

Electrons and holes always created in equal numbers in intrinsic semiconductor.

Common Mistakes

Always use SI units. Check energy conservation accounts for all forms.