HC Verma Chapter 45 Problem 2

Problem Statement

The band gap of a semiconductor is 2.4 eV. Find the maximum wavelength that can be absorbed.

Key Concepts

Band gap, photon absorption

Relevant Formulas

lambda_max = hc/E_g

Step-by-Step Solution

lambda_max = hc/E_g = (6.626e-34 x 3e8)/(2.4 x 1.6e-19) = 1.988e-25/3.84e-19 = 518 nm.

Final Answer

518 nm

Tips and Tricks

Photons with wavelength longer than this pass through the semiconductor.

Common Mistakes

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