NEWS ESCO

The Use Of Oled For Efficient Technology

Digital display might have different sizes, type or names, but one thing they must have in common is their function to deliver visual pleasures to one’s eyes. Many types of digital display in the market today and every each of them may serve different purposes as well. Some are spesifically designed for personal use like smartphone, tablets, monitors, and television. While others like digital signage and video wall are mainly intended for digital advertising, public information or services. Type of display technologies are varied and it is one of key factor that determine their performance. One of them is Organic Light-Emitting Diode or OLED. OLEDs (technology) are mainly used to create digital display in devices such as television screens, computer monitors, and portable systems like mobile phones, handheld games consoles and PDAs.

OLED technology has actually beed discovered back in 1960 but it was not until recently OLED started to attract researchers attention. The basic structure of Oled is a cathode, an emissive layer and an anode. Cathode is also known as emissive (electroluminescent) layer which is a film of organic compund that emits the light in response to an electric current. If cathode functions to inject electrons, anode removes electrons.

Speaking of materials, there are several types of OLED materials. The most basic division (of OLED display) is between small molecule OLEDs and large mollecule ones called Polymer OLEDs or P-OLEDs. Almost all Oled displays made today are SM-OLED based which materials are evaporable and far more advanced than P-OLEDs. P-OLEDs had great promise and are solution processable, it can be used in InkJet printing and spin-coating fabrication methods. Intensive research is currently being performed to develop a more efficient solution-processable SM-OLEDs.

Another interesting division of OLED technology is between Fluorescent and Phosphorescent materials. Fluorescent materials that were first discovered last longer compare to Phosphorescent materials. Yet is much less efficient than its counterpart. Based from this, most researchers agree that the future of OLED technology, particularly in large-area displays and lighting panels, lie with Phosphorescent materials.

Apart from Fluorescent and Phosporescent, there are two main families of driving method that can be found in OLED display: the first one based on small molecules and those employing polymers. Adding mobile ions to and OLED technology also creates a Light-emitting Electrochemical Cell or LEC, which slightly has different mode of operation. OLED displays can either use passive matrix (PMOLED) or active matrix addressing schemes. Active matrix on OLED technology require a thin film transistor backplane to switch each individual pixel on or off. But on the other hand allow for higher resolution and larger display sizes.

Overall, a PMOLED has limits in size and resolution, yet is cheaper and easier to make than an AMOLED. An AMOLED uses an active-matrix TFT array and storage capacitors. While AMOLED displays are more efficient and can be made large, they are also more complicated to make. That is why AMOLED displays are often used for high-end products such as smartphone displays, digital cameras and (expensive) TVs. Korean electronic giant Samsung with its Android smartphones and tablets, is well-known for their use of AMOLED displays. Whereas PMOLED displays are often used in mp3 Players or as a secondary displays on cell phones.

With each specialties of OLED technology, gamers and those who loves the idea of Home Cinema are going to love OLED technology. Oled display is reportedly a lot more superior to plasma technology, as well as being completely devoid of blur and so much more detailed even during fast moving video. In general, OLED display offers brighter pictures and better power efficiency which making the technology ideal for battery powered gadgets.

However, there are major challenges facing OLED technology. The first one is the lifetime of the panels because OLED panels still lag behind plasma and LCD displays, and production scaling beyond Gen- 5.5. Secondly, exploring the possibility of making larger OLED display. OLED display now mainly used in small displays such as mobile devices and MP3 players. Making larger OLED display is possible but absolutely difficult and expensive.

There is also possibility to make a flexible OLED including the electronics and the encapsulation layer. Since 2011, an alternative for transparent OLED display especially for mobile phones and other applications have also been explored.

The manufacturing process of OLED technology lends itself to several advantages over flat panel displays, as follow:

  • OLED technology guarantees lower cost in the future. Theoritically, OLED will able to be printed onto any suitable substrate by an inkjet printer or even by screen printing which making them cheaper to produce than LCD or plasma displays. However, fabrication of the OLED substrate costs more than that of a TFT LCD and will continue until mass production methods lower cost through scalability.
  • Oled technology offers light weight & flexible plastic substrates because it can be fabricated on flexible plastic substrates. As the substrates can be used in such flexible manners, the OLED diplays may be produces inexpensively.
  • OLED display can provides wider viewing angles & improved brightness because OLED pixels directly emit light. Since OLED technology can enable a greater artificial constrast ratio in both dynamic range and static. Pixel colours in OLED technology appear correct and unshifted, even if the viewing angle approaches 90 degree from normal.
  • Better power efficiency and thickness becaue an inactive OLED element does not produce light or consume power. The difference of OLED technology from LCD is LCD filter the light emitted from backlight that allowing a small fraction of light through so the LDC can not show true black color. Dismissing the backlight also makes OLED display feels lighter due to the fact some subtrates are not needed which allows OLED has the potential to be manufactured cheaper.
  • OLED displays can also have faster response time than a standard LCD screen. Whereas LCD displays are reportedly capable of between 1 and 16 ms response time, an OLED technology can have less than 0.01 ms response time. Apart from that, OLED displays can also be run as a flicker display, similar to a CRT, in order to eliminate the sample-and-hold effect that can creates motion blur on OLEDs.

(Date: 5 June 2013; Frida)

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