What is the OLED technology?
At first, I would like to tell what the OLED is? OLED stands for Organic Light Emitting Diode. Inside the OLED there is an emissive electroluminescent layer which made up of an organic compound. Whenever an electric current passes through this organic compound it emits light. It is widely used to make digital displays such as TV screens, monitor of the computer, mobile phone screens or to create the screen for gaming consoles.
An OLED display works without a backlight; so, it will show deep black levels and may be thinner and lighter than a liquid crystal display (LCD). In low ambient light conditions (such as a dark room), an OLED screen can achieve a better distinction ratio than a liquid crystal display, no matter whether the liquid crystal display uses cold cathode fluorescent lamps or an led backlight.
What is OLED made out of? How is OLED display made?
Like an LED, an OLED is a semiconductor device that is 100 to 500 nanometers thick or about 200 times smaller than a human hair. They can have either two or three layers of organic materials; in the latter design; the third layer helps transport electrons from the cathode to the emissive layer. The device consisted of a film of poly(N-vinylcarbazole) up 2.2 micrometers thick located between two charge injected electrodes.
How does it work? How does an OLED display works?
OLED emits light in a similar manner to LEDs; through a process called electrophosphorescence. The process is as follows:
- An electric current flows from the cathode to the anode through the organic layers, giving electrons to the emissive layer and removing electrons from the conductive layer.
- Removing electron from the conductive layer leaves holes that need to be filled with the electrons in the emissive layer.
- The holes jump to the emissive layer and recombine with the electrons. As the electrons drop into the holes, they release their extra energy as light.
Life span of OLED TVs
The lifespan of OLED TVs is considerably lower than that of LCDs and LEDs. OLED displays are made up of organic materials which are not only water phobic but tends to degrade with time. The displays are made up of red, green and blue OLEDs; out of which, blue OLEDs degrade at the much higher rate when compared to red and blue OLEDs. As per a technical report in 2008, the life span of blue OLEDs is 5 years at 8 hours a day. However, some manufacturers claim to increase the life expectancy of these OLEDs. The blue OLEDs have been able to achieve the quantum efficiency of 4% to 6%, where as red and green achieved a quantum efficiency of 20% and 19% respectively.
Advantages and Disadvantages
1. Lower cost in the future
There is no mass production of these TVs yet, but, as soon as the demand for OLED TVs increases in the future, manufacturers will bring down the prices.
2. Lightweight and Flexible plastic substrate
Oled displays can be fabricated on flexible plastic substrates. Plastic substrates are shatter-resistant, unlike the glass displays used in LCD devices.
3. Better picture quality
These TVs enable a greater contrast ratio and wider viewing angle compared to LCDs because OLED pixel emits light directly. Furthermore, OLED pixel always appears to be in a correct position when views from different angles.
4. Better power efficiency
OLED element doesn’t produce light or consume power, allowing true blacks.
5. Response time
The response time of this TVs is great. According to LG, OLED response time is 1000 times faster than LCD, estimated at under 0.01 ms
The biggest technical problem with OLEDs if the lifespan of organic materials. Life expectancy of blue OLEDs is much less than red and green OLEDs.
2. Color Balance
The OLED material used to produce blue light degrades significantly more rapidly than the materials that produce other colors, the blue light output will decrease significantly to the other colors of light.
3. Efficiency of blue OLEDs
blue diodes (430 nm) have only been able to achieve maximum external quantum efficiencies in the range of 4% to 6% while red and blue OLEDs have a much higher efficiency of 20% and 19% respectively.
4. Water damage
Water can damage the organic component of the display. Hence, an improved sealing process is important in the manufacturing process.
5. Outdoor performance
OLEDs show poor performance in terms of brightness and reflectance in ambient light such as outdoors.
Difference between LEDs and OLEDs
LED LCD TVs are in widespread use these days. However, OLED TVs is a new concept to the people. We all know a new technology comes with additional benefits however there are obvious pros and cons of each technology. Earlier TV buyers were forced to answer the question “LCD or Plasma” but now there is no need to answer such questions because Plasma TVs are out of consideration.
OLED TV may be picture-quality king but LED TVs are not going down without a fight, so, which one is better? Let’s find out the answer.
Brightness (Light Output)
In terms of brightness, both TVs have a jammed type of distinction. Both are immensely bright in outdoor light but when it comes to indoor lighting conditions OLED tv seems to be a clear winner.
Another aspect of light output is black level, or how dark a tv can get? OLED wins here because of its ability to turn off individual pixels to produce true black images.
The contrast ratio is the difference between brightness and darkest a tv can get. As an OLED tv can produce absolute black images; it becomes the winner in this category.
High Dynamic Range (HDR)
High Dynamic Range is one of the technologies used to improve the picture quality. It is an extension to contrast ratio, brightness, and many more things. Therefore, OLED TV definitely wins over LED TV because it can relatively produce truly black pictures which the LED TV is not capable of.
The viewing angle of OLED TV is better than that of LED TV. Even when viewing angle is close to 90 degrees; the picture seems perfect. When we look at LED tv closely, the pixels seem to be torn. It only gets better after viewing from a distance which is not same in the case of OLED TV.