In this blog post, we will examine why LEDs are becoming the lighting of the future, replacing incandescent bulbs and fluorescent lights, focusing on their energy efficiency, lifespan, and environmental advantages.
LEDs are currently generating a lot of excitement in the lighting industry. First, LEDs are much smaller than traditional incandescent bulbs and fluorescent lights, and they consume significantly less energy. Additionally, unlike incandescent bulbs, they do not require a warm-up time, and unlike fluorescent lights, they do not flicker when the power is turned on. LEDs emit light immediately when powered on, allowing you to get the light you need right away. But that’s not all. LEDs emit minimal harmful rays such as ultraviolet light and do not require mercury or other gases, making them safe to use even if damaged. Furthermore, LEDs have an almost indefinite lifespan, meaning that once the initial cost is covered, there are no additional expenses. They can also produce a variety of colors, making them suitable for lighting decorations and other applications.
Due to these advantages, LED will soon completely replace fluorescent lights. The amount of resources stored on our planet is limited. However, the population living on Earth is increasing, and assuming that the amount of energy consumed per person remains constant, the total energy consumption will inevitably increase. To cope with this increase in energy consumption, we must either increase total energy production or reduce the amount of energy consumed per person.
To reduce energy consumption, we must reduce the consumption of light energy. Incandescent light bulbs are highly inefficient due to their high energy consumption and short lifespan, and their production and use are now banned. Fluorescent lights, which were identified as a replacement for incandescent bulbs, consume significantly less energy and have become an excellent alternative. However, with the advancement of technology, LEDs have been developed as an even more superior replacement for fluorescent lights.
LED stands for Light Emitting Diode, which is a type of diode. To understand the structure of a diode, there are some concepts you need to know. Atoms are composed of an atomic nucleus and electrons orbiting around it. The positions where these electrons can exist when orbiting the atomic nucleus are discontinuous, and these positions are called shells. When these shells are filled from the inside out, the electrons in the outermost shell are called valence electrons. In chemistry, it is explained that each atom is most stable when it has eight valence electrons, according to the octet rule. Atoms combine with other atoms to share electrons in order to satisfy the octet rule.
Silicon, the primary material for semiconductors such as diodes, has four valence electrons, so it bonds with four surrounding silicon atoms to share one electron each, thereby achieving eight valence electrons. By mixing impurities, n-type and p-type semiconductors are created. An n-type semiconductor is created by mixing atoms with five valence electrons, resulting in one extra electron compared to when silicon is bonded alone. This extra electron is called a hole and carries a negative electric charge. Conversely, a p-type semiconductor is created by mixing impurities with three valence electrons, resulting in one fewer electron compared to when silicon is bonded alone. The areas lacking electrons are electrically positive because the electrons are missing, and these are called holes.
A diode is made by joining an n-type semiconductor, which is created by mixing atoms with three valence electrons, and a p-type semiconductor, which is created by mixing atoms with five valence electrons.
Due to the excess electrons and holes created during the manufacturing process, the diode exhibits its main characteristic, rectification, which is the property of allowing current to flow in only one direction. To allow current to flow through a diode, connect the positive terminal of a power source to the p-type semiconductor and the negative terminal to the n-type semiconductor. This causes the excess electrons in the n-type semiconductor to combine with the holes in the p-type semiconductor, releasing energy in the process.
When a voltage is applied, electrons in a high-energy state combine with holes in a low-energy state, releasing energy equal to the difference in energy levels. By tuning this released energy to the visible light spectrum, we can create an LED that emits light visible to the human eye.
Since LEDs cannot be manufactured to divide energy differences in various ways, a single LED can only emit one color. Therefore, it is impossible to create an LED that emits white light by combining all colors. This issue is generally resolved by combining fluorescent materials or complementary colors. When using fluorescent materials, the principle is similar to that of fluorescent lamps. By combining fluorescent materials around LEDs that emit blue or violet light, the fluorescent materials emit white light. The principle of combining complementary colors to create white light utilizes the principle that light becomes brighter when combined. In particular, combining complementary colors results in white light. Through these manufacturing methods, LEDs that emit white light can be produced.
