OLED has a full-form “Organic Light Emitting Diode” and is pronounced “oh- led .” OLED is a type of flat-screen display that is very similar to an LCD , whereas it does not require any type of backlight. Rather, each LED lights up individually within an OLED panel.
An OLED screen consists of six layers that work together to produce color images. These layers include all these things from the bottom to the top:
1. Substrate – This is the foundational structure that supports the panel; It is usually made of glass or plastic.
2. Anode – A transparent layer that removes electrons when electrical current flows through them.
3. Conductive Layer – This includes organic molecules or polymers such as polyaniline that transfer current to the emissive layer.
4. Emissive layer – This includes organic molecules or polymers such as polyfluorene that light up when current passes through them.
5. Cathode – It injects electrons into other layers when current flows from them.
6. Cover – This is the top protective layer of the screen; Which is typically made of glass or plastic.
How does OLED work?
OLEDs display light through a process called electrophosphorescence. Although it sounds a strange word, but the process is very simple.
Electrical current first flows from cathode (negatively charged) to anode (positively charged), which means that electrons also move the emissive layer. These electrons find ” holes ” (these are atoms that are missing electrons) in the conductive layer and it produces light when they complete these holes. Here the color of light depends on which organic molecules pass the current from the emissive layer.
Since diodes display light up individually in OLED, there is no need for any type of backlight. This means that OLEDs can have darker blacks compared to LED / LCD displays and they also use less electricity. Although they are very thinner, they can be curved or bendable elsewhere. By the way, OLEDs have a lot of advantages compared to LED / LCD displays, that is why making large reliable OLED Screens can be quite valuable.
This is why OLEDs are mostly used in small electronics, such as smartphones and tablets. As OLED production costs begin to decrease and its reliability will increase, then the use of this technology will be seen more in larger screens, such as televisions and computer monitors.