Understanding LEDs and Semiconductors - Arduino Lesson #2

Introduction

• Instructor: Polemic Order from toptechboy.com
• Focus: How LEDs work and understanding the underlying concepts of semiconductors.

Recap from Lesson #1

• Introduction to Arduino microcontroller.
• Wrote initial programs to make an LED blink.

Tools and Materials

• Required: Elegoo Super Starter Kit (~$35).
• Contains various components including LEDs.

Light Bulb Basics

• Invented by Thomas Edison in 1879.
• Operates by passing current through a wire, heating it until it emits light (white-hot).
• Highly inefficient: 95% energy lost as heat, only 5% as light.
• Excessive heat necessitates additional cooling (e.g., air conditioning).

Need for Better Lighting - Enter LED

• LEDs are a more efficient alternative to traditional light bulbs.
• Understanding LEDs requires knowledge of semiconductors.

Basics of Semiconductors

Conductors and Insulators

• Conductor (e.g., copper wire): Allows electrical flow easily.
• Insulator (e.g., plastic, rubber): Does not allow electrical flow.
• Semiconductor: Material that can be tailored to act as a conductor or an insulator based on how it's manufactured and the electrical signals it receives.
• Most digital electronics (e.g., Arduino) are built using silicon semiconductors.

Silicon Wafer Example

• Silicon wafer can contain hundreds of tiny computer chips.

Understanding Semiconductor Physics

Energy Levels in Atoms

• Electrons in atoms occupy discrete energy levels.
• In semiconductors, these discrete energy levels combine to form