TechWeird Stuff

Semiconductors – what are they, and how do they work?

posted by Chris Valentine
Semiconductors are essential for computing

Photo by CC user Lejla peace on Wikimedia Commons

Semiconductors are a substance that the average pays little attention to on a daily basis, although our modern world wouldn’t exist if scientists hadn’t harnessed their bizarre potential more than a century ago.

From radios to computers, they help power the devices that run our economy and entertain us when we get home from a long day at work.

Chief executive of CAE Ryan Jacob has positioned his company to sell high-tech equipment that is built using semiconductors, which are compounds that are essential to the function of many devices assembled today.

What are they, and how do they work? In this article, we’ll explain them in a way that everyday people can understand…

What is a semiconductor anyway?

A semiconductor is a crystal or amorphous solid that has electrical transmission properties that are less than metallic materials, but more conductivity than non-conductors such as ceramics and rubber.

They have significant resistance properties, but have much less of it compared to insulators. Additionally, the resistance they put decreases as it is heated up, which is the opposite effect that occurs when the most other metals get the same treatment.

With the addition of “impurities” to these compounds, the amount of resistance, sensitivity to light and heat, and other effects can be created.

Where are semiconductors used?

With the usable applications of semiconductors being successfully harnessed in the early 20th century, the age of electronics followed soon thereafter, as the malleable properties of these materials allowed them to act as insulators at low temperatures, and conductors at high temperatures.

Semiconductors allowed radios to become a reality, and are still essential components in the computers and smartphones that we depend on in the present day.

In short, any device that makes use or transistors and/or diodes requires semiconductors in order to operate properly.

What properties do semiconductors have?

There are a number of distinct features that make semiconductors stand apart from traditional conductors and insulators. These are as follows:

(1) They have conductivity that varies

Found in their natural state, semiconductors are terrible carriers of electric charges. However, when one modifies a semiconductor by either doping or gating, the balance of electrons is disturbed, allowing a current to flow where it wasn’t possible to do so before.

(2) Some give off light

In some semiconductors, the presence of stimulated electrons has the effect of it giving off light instead of emitting heat. As a result of this unique property, these types of semiconductors are used to create light emitting diodes (LED’s) and fluorescent quantum dots.

(3) Others give off heat

As alluded to in the last point, another effect of semiconductors is that they can give off heat. This can be taken advantage of by making it into a thermoelectric generator, which would take that heat and convert it into additional electricity.

This has applications in power plants, as a fuel efficiency improvement mechanism in automobiles, and to squeeze every last drop out of electricity production aboard space probes.

How do they work exactly?

The primary elements that are used as semiconductors by industry – carbon and silicon – are almost pure insulators in their natural form.

However, using outside intervention by inserting a substance such as phosphorous or boron, electrons are introduced that creates an imbalance on the carbon or silicon wafer, thereby turning it into a conductor, albeit an imperfect one.

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