The difference between LED lighting and OLED lighting

- Dec 07, 2015-

LED and OLED as a new semiconductor lighting technology, known as the fourth generation light source or green light, compared to traditional lighting products, it has energy-saving, environmental protection, long life, small size and other characteristics, it can be widely applied in various directions , display, decoration, backlight, general lighting and urban landscape and other fields.

Thus, in recent years some of the world's developed countries are actively developing LED and OLED Lighting. However, LED and OLED due to the different works and production process, there are their own characteristics.

LED stands for light-emitting diode, the general use of III-IV family of inorganic semiconductor materials and chemical vapor deposition (CVD) process. As with conventional semiconductor industries, its high cost manufacturing process, it is difficult to achieve large size.
Therefore, LED can only be applied in the form of a point light source. Indoor general lighting field, in order to achieve a certain space of illumination, LED requires high brightness, so in order to prevent glare, resulting in soft light, LED lampshade often must be installed to use. But this way, the luminous efficiency of LED lamps will drop.

If you want to make use of LED surface light source, such as an LCD backlight, you need a combination of a plurality of LED and light guide plate with complex optical systems. In addition, LED luminous efficiency as the temperature rises and abrupt decline.

Because LED volume is very small, the heat generated during the operation of hard timely dissemination out, it must be equipped with a heat sink for the LED lamps. Based on the above for several reasons, the advantages of LED light source technology such as luminous efficiency, light and cost advantages in the production of a lamp post will be greatly discounted.

Currently covering white LED is generally used phosphor powder blue LED on the way to achieve (as shown). Phosphor powder excited by blue light emitted from the LED will produce a yellow light, white light and then mixed together with blue LED itself. Although this method is low cost, but there are many disadvantages.

On the one hand, this approach produces white color rendering index will not ideal, namely the object under white light color such deviations occur, making it unsuitable for use in high color quality requirements of the occasion; on the other hand, the phosphor powder aging faster than a lot of the blue LED, the white light emitted will lead to blue drift, thereby shortening the life span.

OLED stands for organic light emitting device, by definition, OLED is an organic semiconductor material-based devices. Materials used are small molecule OLED and polymer of the points, the current industry of mainly small molecule organic material-based.

Due to the small molecule OLED lower cost glass as the substrate, and a large area vacuum thermal evaporation deposition process, it is a priori a surface light source OLED technology. OLED process technology process technology without LED ultra-high vacuum and high temperature environment, cost competitiveness is much higher.

Theoretically the organic material than inorganic semiconductor materials is much lower, but is currently limited to the industrial scale production of material utilization and other factors, the cost of organic material is still very high. However, with the expansion of industrial scale, the cost of organic material will be substantially reduced.

OLED light uniformity generally soft, close to the Lang Park (lambert) radiation distribution, so OLED itself is almost a fixture without matching shade to use. At present, mainly in the hair red, green and white OLED (yellow) and blue three basic colors of organic material mixed successively superimposed.

In addition, the characteristics of the emission spectrum of the organic material is its half-peak width is very wide, so the white OLED spectrum no large gap, which makes the color rendering index of OLED light source is very good, especially suitable for indoor general lighting, or even professional photography and other applications. Furthermore, by adjusting the proportion of each color light-emitting materials, it can produce any color of light to suit different applications.

Because OLED has a very large light-emitting area, the heat generated during operation can be promptly dissipated, without heat sink. So OLED can be very thin, space-saving costs. In addition, OLED can be designed into a variety of shapes, greatly expand the OLED lighting applications in the field of space in the Art Deco.

OLED killer feature can be transparent, even to achieve the traditional lighting application completely unimaginable ways, such as the OLED fabricated on glass windows during the day to let natural light shine through, as the use of lighting at night.

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