OLED Display

- Aug 19, 2020-

The simplest form of an organic light-emitting diode is composed of a layer of light-emitting material embedded between two electrodes. When the voltage is input, the carriers move through the organic layer until the electrons and holes recombine, so that energy conservation is achieved and the excess energy is released in the form of light pulses. At this time, one of the electrodes is transparent and the light emitted can be seen. Usually composed of indium tin oxide (ITO).


Organic light-emitting diodes take advantage of the characteristics of electron emission: certain materials emit light when current passes through. And from every angle, it is clearer than a liquid crystal display.


OLED display principle


The simplest form of an organic light-emitting diode is composed of a layer of light-emitting material embedded between two electrodes. When the voltage is input, the carriers move through the organic layer until the electrons and holes recombine, so that energy conservation is achieved and the excess energy is released in the form of light pulses. At this time, one of the electrodes is transparent and the light emitted can be seen. Usually composed of indium tin oxide (ITO).


OLED display materials


The color of light is related to the material. One method is to work with layers of small molecules, such as aluminum oxide. Another method is to embed activated pigments in long polymer chains, which are very easy to melt and can be made into coatings.


OLED is more efficient


Electron flow and carriers are usually not equal. This means that when the dominant carriers pass through the entire structure layer, they will not encounter electrons coming from the opposite direction, resulting in high energy consumption and low efficiency. If one organic layer is replaced by two different organic layers, better results can be achieved: when the boundary layer of the positive electrode supplies carriers, the negative electrode side is very suitable for transporting electrons, and the carriers are in the middle of the two organic layers When passing, it will be blocked until there are carriers moving in the opposite direction. In this way, the efficiency is significantly improved. After the very thin boundary layer is recombined, small bright spots are produced, which can emit light. If there are three organic layers, which are used to transport electrons, transport carriers, and emit light, the efficiency will be higher.


OLED emits light, but LCD does not emit light


The biggest difference from the liquid crystal display (LCD) is that the organic light-emitting diode itself is the light source. In a liquid crystal display, the input voltage is different, the tiny liquid crystal will change the direction, they will pass/block the white light emitted from the background light source, this principle also limits the viewing angle. From the side, the effect is poor, or invisible at all. If a liquid crystal display has a pixel error due to the wrong color of the light, this error will almost never occur in an organic light emitting diode