What is OLED Displays and how does it works?

Image credit: https://blogs.systweak.com/2017/12/what-is-oled-screen-and-its-types

Do you know what the OLED displays is? All of you have heard about this OLED display recently, because in both the iPhone X and Samsung Galaxy Note 8, this time Manufacturer has used the OLED Display. Not only is it providing a nice look to phones, but it offers a lot of new features phones. Since this OLED display is very precious, it is being used only in high end phones and other Tech Gadgets for now.

Many of us would have heard about this as a new version of the LED . Organic LED but do you have complete knowledge about it. If not, please stay with me and read this article completely, till then you will get complete information about the OLED display. Then without delay, let us know what is the OLED display and how it is different from the other LED, then let’s start.

Also Read: Gmail is going to get new features

What is OLED

The complete form of OLED is Organic Light Emitting Diodes . This is a flat light emitting technology. Which is made of series of organic thin films, is done together in the middle of the two conductors in the series. Whenever electric current is passed from within them, then it emits a bright light. OLEDs are an emissive display that has no need for backlight, with which they are very thin and are much more efficient than LCD displays .

OLED displays are not only thin and efficient but also provide the best image quality. With this they can be made transparent, flexible, foldable and rollable, stretchable also in the future. Therefore, it is not wrong to say that the OLED is also the future of display technology. It requires very little power to run. OLED is used in mobile phones, smartphones and gaming devices.


What is OLED Technology

OLED panels are made of organic materials, and they emit light only when these are passed to electricity. Since OLEDs are backlight and filters (such as in LCD displays), they are more efficient, easy to make, and very thin – they can be easily flexible and even rollable. OLEDs have the best picture quality – brilliant colors, infinite contrast, fast response rate and wide viewing angles are some of the main features. OLEDs are also used for OLED Lighting, where it can be made of thin, efficient and without any metals.

Working of OLEDs

The main component of the OLED display is OLED emitter – which is an organic-based material and it emits light only when it is applied to electricity. The basic structure of an OLED is such that in which an emissive layer is sandwiched, between a cathode (which injects the electrons) and an anode (which removes the electrons).

OLEDs generally work similarly to conventional diodes and LEDs, but instead of using layers of n-type and p-type semiconductors, organic molecules are used to produce electrons and holes. A simple OLED is made up of six different layers. Top and bottom have protective glass or plastic layers. The top layer is called “seal” and the bottom layer is called “substrate”.

Between these layers, there is a negative terminal (sometimes called cathode) and a positive terminal (sometimes called anode). Finally, anode and cathode have two layers, which are made of organic molecules, whose emissive layer (where light is produced, which is next to the cathode) and the conductive layer (which is anode Is said next to). Modern OLED devices use lots of layers, so that they can be made more efficient and durable, but all of these basic functions remain the same.

How OLED Panel is Made

An OLED panel consists of a substrate, backplane (electronics – the driver), frontplane and an encapsulation layer. OLEDs are very sensitive. Encapsulation layer is also very critical with oxygen and moisture.

Substrate and backplane are very similar to any OLED display, like an LCD display, but the front plane deposition is very unique, of OLEDs. There are many ways to do organice layers to deposit and pattern. In most of the time, all OLED displays are created by vacuum evaporation, along with the Shadow Mask (FMM, Fine Metal Mask) is used to pattern it. This is a very easy method but it is very inefficient (many materials are wasted here) because it is hard to scale up in a large substrate.

Some OLED materials are soluble, and it is deposited with the use of printing methods, here ink-jet printing is used. This technology has not yet been commercialized, but OLED makers believe that ink-jet printing can also be scalable, efficient and cheap so that its use can be used to deposit OLEDs.

Why are these OLEDs called Organic?

OLEDs are therefore organic because they are made of carbon and hydrogen. But the fact is that they do not have any relation with organic food and farming – OLEDs are very efficient but with no bad metals used in it – we can say that they are right There is a real green technology in Mene.

How do OLED Light Emit

These questions often come in the minds of many people, how does light generate from OLED? Here you will be giving complete information about this topic to the people.

1. If an OLED is to be burnt then first we have to attach it to a voltage source, which is applied across anode and cathode.

2. As soon as the electricity starts to flow, then cathode receives electrons from the power source and the anode loses them (or else the “hole receives,” if they look at it) .

3. Now we have a situation where the added electrons emissive layer is negatively charged (which is similar in the n-type layer such as junction diode) , but the same conductive layer becomes positively charged (which is similar p-type material).

4. Positive holes are very mobile, because of negative electrons, they can easily jump from boundary to the flow from the flow to the emissive layer. When a Hole (A Lack Of Electron) to meet an electron, these form the two things that cancel each other and the release of a burst of energy which is also known as a particle of light- photon of whom it occurs. This process is also called recombination because there is a number of times in 1-second, so that the OLED produces continuous light until the current continues to flow.

If we want, OLED can be made to create color light, for which we have to put a colorized filter under the plastic sandwich at the bottom of the glass or plastic top or bottom layer. If we will keep the same number of thousands of red, green, and blue OLEDs with each other and independently switch on and off, then those pixels which will work in a conventional LCD screen will help us to understand complex, hi- resolution can produce colored pictures.

Types of OLEDs

There are two different types of OLED main.

1) Traditional OLEDs:  which use small organic molecules and which are deposited on top of the glass, to create light.

2) Light-Emitting Polymers:  These are the OLED of the second deck, which use large plastic molecules called polymers. These OLEDs are also called light-emitting polymers (LEPs) and sometimes called polymer LEDs (PLEDs). Since they are printed on plastic (often a modified, high-precision version is inserted into the inkjet printer) in place of glass, due to which it is even more thin and more flexible.

OLED Materials

By the way, there are many types of OLED materials. Which is the most basic division is within small-molecule OLEDs and large molecule ones (those of which are called Polymer OLEDs, or P-OLEDs). Today all commercial OLEDs being used are SM-OLED-based. P-OLEDs had the first name because they were naturally resolved (and so used to be inkjet printing and spin-coating fabrication methods) – but now P-OLEDs are not much popular because their performance is now SM-OLEDs There is absolutely no such thing as. There are many intensive research done so that more efficient solution-processable SM-OLEDs can be developed.

OLED emitter materials can be classified either fluorescent and in phosphorescent. Fluorescent materials can stay tick for a long time but they are not more efficient as phosphorescent materials. Most OLED displays now use phosphorescent emitter materials – but just leaving the blue color which is still fluorescent, so that its life is not as good. Universal Display Corporation is currently researching PHOLED, and has also hold its own basic patents in the same area.


These terms are mainly related to the driving method of the OLED display. A PMOLED ( Passive-Matrix OLED) is always limited in size and resolution, but these are very cheap and it is very easy to make them if we compare AMOLED (using these Active-Matrix).

An AMOLED always uses active-matrix TFT arrays and storage capacitors. These displays are very efficient and they can also be made bigger, they are very difficult to build, compared to PMOLED.

PMOLED displays are used in small devices and secondary displays AMOLEDs are used in smartphones, tablets and TVs.

Advantages of OLEDs

OLEDs are superior in many reasons from their rival LCDs Here I have provided some information about this subject.

  • They are very thin.
  • Along with this they are also lighter and are also very flexible.
  • Being too bright, they do not need any backlight.
  • They consume very little power compared to LCD. By which, portable devices have better battery life.
  • Compared to LCD, their refresh rate is very high, so you can see fast-moving pictures here.
  • These can produce truer colors very well and that too with big viewing angle.
  • The curtain to make them is too low compared to the LCD.
  • OLED is available in very different colors, so that they are very versatile.
  • There is no need for a warm up period to start in it, it starts instantly.
  • They are dimmable so they can be used for ambient lighting.
  • These do not produce heat, therefore, they are also called cold light source.
  • Their efficiency level is more than halogen and incandescent lights.

Disadvantages of OLEDs

Well OLEDs have more advantages but there are some disadvantages too, so let’s know about them.

  • They do not last for long as the stagnant organic molecules start slow down.
  • With this, they are very sensitive to water and moisture. Since these homes do not apply much in the live TV sets, but this real challenge brings in the portable device (SmartPhones).

Application of OLEDs

As we know that the technology of OLEDs is very new. They are being used in very few places right now. Where people are using LCD and LED, they have just stepped into the market. However, due to its many good features, it has started to be used much more now.

  • OLED Display
    are also being used mainly in Mobile and other electronic gadgets at the display level.
  • Digital Watches
    Since their weight is very low, they are also foldable, with this they use very little power, so they are being used in Apple Smart Watch.
  • Large companies like Smart Phones Apple and Samsung have used OLED in their new phones because they not only give phones a nice look, but also provide a lot of features with it.
  • OLED TVs
    Its now being used in Television too because it provides viewers with truer colors and with it the wider viewing angle, those who see them have a very good experience.


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