What is OLED?

July 11, 2020, at 2:54 pm

What is OLED?

OLED is a flat light emitting technology, kind of LED (Light Emitting Diode), with a small adjustment that the component that produces light is comprised of a thin layer of organic compounds.

This organic semiconductor layer is placed between the two conductor electrodes. When electrical current is applied, a bright light is emitted. They are emissive displays that don’t need a backlight and so, are thinner and more efficient than LCDs – which do require a white backlight.

It is mostly utilized for flat panel displays, mobile devices, and smartphones. OLEDs have excellent picture quality; Excellent colors, supreme contrast, quick response rate, and wide viewing angles.

OLEDs can also be used to make OLED lighting.

So what’s organic about OLEDs?

OLEDs are organic because they are made from carbon and hydrogen. There’s no connection to organic food or farming – although OLEDs are very thin and efficient and do not contain any harmful metals; therefore, it’s a real green technology.

There are two types of OLEDs:

• Based on small molecules

• Using polymers (large-molecules)

Working of OLEDs Organic LED’s work almost the same way as traditional LEDs, with slight adjustments. In this, instead of n-type and p-type semiconductors, organic molecules are utilized to produce electrons and holes. There are six layers of OLEDs. The top layer is known as the seal, while the bottom layer is called the substrate. There are two terminals between the top and the bottom layers – anode (positive terminal) and the cathode (negative terminal). In the middle of these terminals, there are the organic layers; One is the emissive layer, and the other is the conductive layer.

A voltage is connected to the anode and the cathode. Electricity starts circulating, and the cathode begins to receive electrons while the cathode begins to lose them. As the particles are added, the emissive layer becomes negatively charged at this point, while the conductive layer becomes positively charged. The positively charged holes begin jumping towards the emissive layer. When the positive hole meets the negatively charged electron, a photon is produced, which is a particle of light.

OLED technology today The leading AMOLED (active-matrix organic light-emitting diode – a display device technology used in smartwatches, mobile devices, laptops, and televisions) producer today is Samsung, who’s making over 400 million displays a year, mostly smartphone-sized AMOLEDs (flexible and rigid). LG Display is the world’s leading (and only) OLED TV panel maker, and LG is also starting to create small-sized flexible OLEDs now. Advantages of OLEDs

  • These are superior to LCDs (Liquid Crystal Display – a type of flat panel display that uses liquid crystals in its primary form of operation.

  • These are thinner, lighter, and flexible.

  • The response time is faster than the previous generation of LCD screens.

  • They deliver true colors with a better viewing angle.

  • Improved image quality – better contrast, higher brightness, fuller viewing angle, a more comprehensive color range, and much faster refresh rates.

  • Lower power consumption.

  • A more straightforward design that enables ultra-thin, flexible, foldable and transparent displays

  • Better durability – OLEDs are very durable and can operate in a broader temperature range

Disadvantages of OLEDs

  • These have comparatively less lifeline than the LCDs.

  • The organic molecules degrade over time.

  • These are very sensitive to water.

  • OLEDs aren’t perfect. First of all, it costs more to produce an OLED than it does to produce an LCD – although this should hopefully change in the future, as OLEDs has a potential to be even cheaper than LCDs because of their simple design (some believe that future OLEDs will be printed using simple ink-jet processes).

  • OLEDs have a limited lifetime (like any display, really), that was quite a problem a few years ago. But there has been constant progress, and today this is almost a non-issue.

Today OLEDs last long enough to be used in mobile devices and TVs. OLEDs can also be problematic in direct sunlight because of their emissive nature. But companies are working to make it better, and newer AMOLEDs (such as Samsung’s Super AMOLED and Super AMOLED Plus and Nokia’s CBD displays) are quite good in that respect – some even consider them superior to LCDs.

  • Material lifetime and efficiency (especially of the blue material)

  • Soluble OLED material performance and production processes

  • Flexible OLED encapsulation

  • Better backplane materials for flexible OLED and foldable ones

  • Scaling of evaporation processes for direct emission OLEDs beyond Gen-6

  • In conclusion, besides its sleek elements, they provide the best image quality ever, and they can also be made transparent, flexible, foldable, even rollable, and stretchable in the future. OLEDs represent the future of display technology!