LED adopts metal material, however, OLED uses organic material. Their emitting principles are the same, the difference is that OLED does not need backlight, because it is composed of light-emitting diode array and it can emitting itself. It is brighter and thinner than LED LCD display, and it will become an alternate of LED LCD display in the future. LED LCD display needs backlight. Its brightness is common, and displays unclearly under sunlight, but it is the most widely used at present.
LED is the abbreviation of Light Emitting Diode, composed of the Gallium (Ga), Arsenic (As), Phosphorus (P), Nitrogen (N) and other compounds. It is a solid-state semiconductor device that can convert electric energy into visible light. Its basic structure is an electroluminescent semiconductor material chip, curing to the fixture with silver glue or white glue. And then use silver wire or gold wire to connect the chip and circuit board, and then seal it around by epoxy resin to protect the internal core. Then finally install the external shell. That’s why LED lights’ seismic performance is good.
LED applications are related to mobile phones, lamps, household appliances and other daily household appliances and machinery production, which can be divided into two categories: one LED tube applications, including backlight LED, infrared LED; the other one is LED LCD display. Currently, there are still some gaps for the LED basic materials manufacturing in China and international. But so far for LED LCD display, China keeps the same level as international for the design and production technology. LED LCD display is composed of light-emitting diode array. It adopts low voltage scanning driver, with low power consumption, long life, and low cost, high brightness, less failure, larger viewing angle, and long visual distance characteristics and so on.
OLED is organic light-emitting diode, also known as organic electroluminescent display, and organic light-emitting semiconductor, which light-emitting principle is different from liquid crystal display (LCD). OLED display technology is not the same as traditional LCD display. It doesn’t need backlight, and adopts a very thin organic materials coating and glass substrates, or specially will use plastic substrates. When there is current through, these organic materials will glow. Moreover, OLED display screen can be made lighter and thinner with greater viewing angle, and can significantly save energy. However, although OLED which with better technology will replace the TFT and other LCD in the future, the organic light-emitting display technology still remains short life, difficult to realize large screen and other defects.
In order to illustrate the OLED structure, we can imagine each OLED unit as a hamburger, and the luminescent material is the vegetables in the middle. The display unit of each OLED can be controlled to produce three different colors of light. OLED and LCD, there are both active and passive modes. Under passive mode, the units which selected by the row and column address will glow. And under active mode, there is a thin film transistor (TFT) behind OLED units, and the units will glow driving by TFT. Active mode OLED is more energy-saving than the passive mode, and its display performance is better.