Silicon is not suitable for fabrication of light emitting diodes because it is

Solution (By Examveda Team)

Question: Why isn't silicon used to make light-emitting diodes (LEDs)?

Explanation:
LEDs work by emitting light when electrons fall from a higher energy level to a lower one. This happens most efficiently in materials with a direct band gap.

Silicon is an indirect band gap semiconductor. This means that when an electron drops to a lower energy level, it doesn't directly emit a photon (light particle). Instead, it often loses energy through other processes (like vibrations in the crystal lattice) which don't produce light.

Therefore, silicon isn't suitable for LEDs because its indirect band gap makes it inefficient at converting electrical energy into light. Materials like gallium arsenide (GaAs), which have a direct band gap, are much better choices for making LEDs.

The correct answer is A: An indirect band gap semiconductor