Chapter 12, Problem 12.25CP

Interpretation Introduction

Interpretation:

The correct match of energy level diagram for blue and red LEDs should be determined.

Concept introduction:

The quantum dots of any solids can be defined as the semiconductor particles that have size in nanoparticle range and changes color with change in diameter of particles. These quantum dots are used in solar cells, LEDs, quantum computing, medical imaging. Since size of nanoparticle is intermediate between the bulk solids and atoms thus the spacing between electronic energy also has intermediate value between large for atoms and continuous band for bulk solids. Therefore, spacing between bands depends on size of nanoparticle. These different energy gaps can create valence band and conduction band and can give different colors on transition.