What Is a Multi-Color LED?

This is a new type of light emitting diode that emits white and colorful intermediate colors. LEDs are made of a combination of P-type semiconductors with many positive holes (electron defects) and N-type semiconductors with many electrons. This is an epoch-making achievement, and has been applied in many fields.

Multicolor LED

Right!

This is a new type of light emitting diode that emits white and colorful intermediate colors. LEDs are made of a combination of P-type semiconductors with a lot of positive holes (electron defect) and N-type semiconductors with a lot of electrons. They use a bank structure to emit light. This is an epoch-making achievement, and has been applied in many fields.

LEDs are made by combining a P-type semiconductor with many positive holes (electron defect) and an N-type semiconductor with many electrons. After a certain voltage is applied, the junction surface of the two semiconductors emits light. And, compared with traditional incandescent light bulbs and fluorescent lamps, LEDs have many advantages.

First, it lasts a long time and is dozens of times longer than incandescent light bulbs. Low power consumption, only a fraction of incandescent light bulbs. In addition, there is less heat generation, and the time from the voltage application to the lighting is short. According to these advantages, LEDs are first used as pilot lights to show the use of electrical products, road lights, street lights, etc., and the scope of use is expanding.

However, the color problem has not been solved. LEDs emit light for the semiconductor unit itself, so the color depends on what kind of semiconductor material is used. For this reason, in order to achieve the desired color, the appropriate materials have been searched since the 1980s. In the 1990s, the three primary colors of light, red, blue, and green, were finally available. LEDs such as orange, yellow, and purple have also been developed. However, it is difficult to obtain intermediate colors of these colors.

In addition, no white display materials were found. There are three methods to obtain white: (1) LEDs emitting three primary colors of red, blue, and green are lit at different intensities at the same time; (2) blue and yellow, Do the same for the two LEDs that are auxiliary colors, such as green and red. (3) Wrap the blue LED with a special phosphor. However, the first two methods are very difficult to adjust the intensity of the LEDs separately, and the third method is also useful for the difficulties of large energy loss of the phosphor.

Two dam-shaped structures: high and narrow dam-shaped, low and wide dam-shaped & copy; Graduate School of Engineering, Kyoto University

Jingda and Nichia s LEDs broke this situation, using thin sapphire crystals as the substrate, on which gallium nitride was crystallized and formed into a quasi-dam-like shape. In the past, LEDs only had a flat surface, and a color was displayed from this surface. In contrast, the color of the LED emitted from the top of the dam-like structure is different from the color emitted from the side, and the two colors are mixed to emit mixed light.

The research team produced two types of high and narrow dams and low and wide dams this time. The light emitted by the dams is red on the high dam, blue on the side, and yellow on the low dam. Is blue. By changing the ratio and configuration of the two dam structures, three colors of red, blue, and yellow can be mixed according to various ratios, thereby achieving white and colorful intermediate colors.

In addition, since no phosphor is required, energy efficiency is high. If this LED can be put into practical use, in addition to expanding the white LED market, it can also be adapted to surgical lighting that requires subtle colors and as a light source for photographic photography, etc., and can be developed to more uses. ^[1]