Module 5: Semiconductors

Welcome to Module 5, which will present a comprehensive introduction to semiconductor devices.

Semiconductors are materials that exhibit electrical conductivity that is between conductors and insulators.

Semiconductors are arguably the most important materials of the last century, and their use has ushered in the digital age. In the world of electronics, few topics are as important or exciting.

Stepping Into the World of Semiconductors

Lesson One: Semiconductors will provide a solid overview of semiconductor materials. The electrical and crystalline properties will be covered, as well as the development of semiconductor technologies. Semiconductor devices rely on both electrons and electron holes, and we’ll explore the concept of electron holes, or ‘holes’, in detail. In order to understand semiconductor devices we must also look more deeply into the physics of electrons in the material. To make this (much) easier, we’ll also learn about a new tool called a band diagram.

Something that may be surprising is that semiconductors are pretty useless on their own. What makes semiconductors useful is our ability to ‘dope’ a pure semiconductor crystal with different atoms in order to change their electrical properties.

Lesson Two: Semiconductor Doping explores the concept of doping; what it means, why we do it, and what we can do with it. We’ll learn about both p-type and n-type doping in silicon-based semiconductors. In the process, we’ll learn a lot more about electrons and holes, as well as the band diagram.

Now that we’ve learned about semiconductors, it’s time to start making some interesting devices.

Lesson Three: P-N Junctions tackles the first useful semiconductor devices. P-N junctions are incredibly useful; almost all diodes are a type of P-N junction. In addition, transistors are essentially combinations of P-N junctions stacked together. By developing a solid understanding of the P-N junction, we will be able to understand much more complex semiconductor devices.

With P-N junctions behind us, we can now apply our newfound knowledge directly in order to explore one of the most important classes of semiconductor devices: diodes.

Lesson Four: Diodes introduces the P-N junction diode and includes practical guidelines and circuit problem examples to help you on your way to diode mastery.

Lesson Five: Light Emitting Diodes (LEDs) tackles one of the most important and common semiconductor components. LEDs are ubiquitous in the modern world, used in televisions and cell phones as well as lighting applications. They can provide a handy reference in circuit building, and are often used as an indicator where they are much safer and more efficient than either incandescent or fluorescent light options.

Lesson Six: Zener Diodes covers one of the most interesting and useful types of diode. Unlike other diodes, Zener diodes are designed to be used in reverse bias configuration. They are used to provide a stable voltage drop despite significant variations in current.

Lesson Seven: Transistors takes us deep into the heart of the most important component in the field of semiconductors. Transistors allowed computers to transition from vacuum tubes and relays to solid state components that could be scaled to incredibly small sizes in a phenomenon known as Moore’s Law.

We begin our journey into the world of semiconductors with the aptly named:

Lesson One: Semiconductors

About This Course

On each page, you will find a drop-down lesson menu at the top of the page and a content listing of the module at the bottom of each page for easy access if you’d like to review past lessons or jump around.

If you’re a newbie, we recommend reading through each lesson before moving on to the next. As in any complex subject, the more you learn, the more you will understand- don’t be surprised if you find it difficult at first- because the farther you go, the more you will be able to understand. Each new concept builds on the last, but also enhances your understanding of what you thought you already knew.

As always, if you have any questions, don’t hesitate to reach out!