In this blog post, we’ll explore the principles and roles of semiconductors hidden within the devices we use every day, and discover just how crucial this technology is to our daily lives.
A man wakes up to the sound of his alarm clock in the morning. He turns on the TV with the remote to watch the morning news, shaves with an electric razor, and then enters the bathroom—equipped with automatic sensors—to wash his face. After getting ready for work, he takes the bus to the office. As soon as he arrives, he starts working on his computer in an office equipped with air conditioning and a coffee maker. Occasionally, he receives text messages on his cell phone. After finishing his daily routine and returning home, he enjoys his leisure time on his laptop. Can you believe that all the devices mentioned so far contain semiconductors? Just like this, we are living in a sea of semiconductors, and it is no exaggeration to call our current era the “Kingdom of Semiconductors.” However, we still don’t know much about semiconductors, even though they are deeply embedded in our daily lives. In many cases, we don’t even properly understand how semiconductors are made, how they work, or where they are used. In this article, we will explore the principles and applications of semiconductors.
A semiconductor is essentially a device that allows current to flow when it receives an external stimulus called voltage. Just as water flows in the direction of the wind when it blows over a river, electrons and holes within a semiconductor create and carry an electric current. Electrons carry a negative (-) charge, while holes carry a positive (+) charge, so they move in opposite directions when current flows. For example, when current flows to the right, the holes move to the right and the electrons move to the left. However, these particles do not always move in a fixed direction. Just as people need to eat to work, electrons and holes must receive energy in the form of voltage to move. In this way, the movement of electrons and holes driven by voltage causes current to flow within the semiconductor.
At this point, it may seem as though semiconductors function like conductors that allow current to flow. If so, why are they specifically called “semiconductors”? A conductor refers to a material that allows current to flow easily, whereas a semiconductor is a material that can either allow or block current flow depending on the circumstances. In other words, the prefix “semi” does not mean that only half the current flows, but rather that the flow of current changes depending on the conditions. Semiconductors also have positive (+) and negative (-) polarities; when a voltage is applied in a specific direction, current flows, and when applied in the opposite direction, the current is blocked. It is similar to how, on a moving walkway, you can walk quickly if you’re moving in the same direction as the walkway, but if you move in the opposite direction, you end up treading water. Similarly, in a semiconductor, the flow of current is determined by the direction of the voltage.
This property of semiconductors enables the power management functions essential to various electronic devices. For example, imagine how inconvenient it would be if you had to unplug every device every time you turned off your computer. In addition to power management, semiconductors act as switches within electronic devices, allowing for precise control of their functions. The reason we can watch LCD TVs is that the tiny light bulbs on the screen turn on and off in a specific sequence. Furthermore, the adjustment of fan speed in electric fans or air conditioners is also achieved through the operation of semiconductors. In this way, the switching function of semiconductors has established itself as one of the core technologies of modern electronic devices.
The scope of semiconductor applications is extremely broad. As mentioned earlier, semiconductors are found in almost every device in our daily lives. Semiconductors come together to form a single circuit, and multiple circuits combine to form a single chip that performs specific functions. Various devices, such as temperature controllers, pressure sensors, and graphics cards, are composed of these chips. Light-emitting devices like LEDs also utilize semiconductors and are used in light bulbs and LED TVs. The cameras in digital cameras and smartphones can capture photos and videos by responding to light sensitivity, and the CPUs in computers and calculators are also made of semiconductor circuits. As such, semiconductors play a pivotal role in various industries and perform diverse functions depending on their application.
We have now explored the principles and applications of semiconductors. We can see that what appears to be a simple principle plays a crucial role in practical use, and its scope is far broader than one might imagine. We already live in an era where life would be difficult without semiconductors. South Korea is also a global leader in the semiconductor industry, which serves as a major pillar of the nation’s growth engine. The development of the semiconductor industry was a key factor in enabling Samsung Electronics and LG Electronics to grow into global corporations. The semiconductor industry is expected to continue evolving through technological innovation in the future. It is also worth looking forward to how our lives will become even more prosperous alongside the advancement of semiconductor technology.
