In the future, mobile computing applications will have requirements which exceed what is currently available. Display technologies which are robust, unbreakable, and flexible will be crucial to the forecasted technological advancement. To meet this need, it is expected that organic light-emitting diodes (OLED) replace the now-ubiquitous LED devices available.
But before we go any further, what is an OLED and what are the applications?
OLED technology is based on the principle of electroluminescence- an optical phenomenon in which light is emitted from a material in response to electric current passing through that material. The major application of OLED is in the area of digital displays like television screens, computer screens, mobile phones, digital cameras, etc.
How does an OLED Work?
The OLED display is either driven by the passive-matrix (PMOLED) control scheme or the active-matrix (AMOLED) control scheme. For the PMOLED, the row in the display is controlled step-wise while the AMOLED involves controlling the individual pixels, switching them on or off directly using a thin-film transistor.
An OLED display is able to function properly even without a backlight since visible light is being emitted. This means that deep black levels of light can be displayed. Also, the display can be thinner and lighter than a liquid crystal display (LCD). The contrast ratio of OLED display devices also trumps that of LCDs in low ambient light conditions.
Superiority of OLED
The unique nature of OLED and the manufacturing process provides a plethora of advantages when compared to flat panel displays. Some of the benefits are discussed below.
OLEDs have better Power Efficiency and Thickness
An LCD will filter the emitted light from a backlight and then allow a fraction of light to pass through, meaning that it’s impossible for LCDs to show true black. An inactive OLED, on the other hand, neither produces nor consumes power, making it ideal for the display of true black colors. In addition, when the substrates that aren’t needed are removed, the OLEDs become even lighter.
Response Time of OLEDs is Faster
When compared to LCDs, the response time of OLEDs is far better. Under standard testing conditions in the laboratory, it was seen that the fastest modern LCD attained response time as low as 1ms for color transition and the refresh frequency was as high as 240 Hz.
For OLEDs, the response time was tested by LG and it was found to be 1000 times faster than LCDs. This means the refresh frequency can be up to 100 kHz. This feature means that it is possible to design OLEDs to work like a strobe light.
OLEDs are Lightweight
One common hallmark of technological advancement is miniaturization and flexibility. Thankfully, OLED displays are fabricated on flexible plastic substrates and this is even causing researchers to consider using the material for other designs. Some other applications might include roll-up displays embedded in fabrics. OLEDs are also shatter-resistant.
Disadvantages of OLEDs
Easily Damaged by Water
Remember that they are organic materials. This means that they are prone to damage caused by water, hence, it is important that the method of sealing is improved to ensure that the devices respond better to water.
This is one of the biggest and most worrisome drawbacks to OLEDs. A report on OLED TV panels showed that the blue luminance degrades by 1000 hours after 1000 hours while the red and green degrade by 7% and 8% respectively.
OLEDs are perfect for displaying an image that is fundamentally black, consuming just 40% of the power consumption of an LCD for the same image. However, if the image has a white background, the power consumption will be about 3 times more.
Application of an OLED
OLED lighting has the illumination of higher quality, varied panel shapes, and better-diffused light sources. Philips Lighting has OLED lighting products, sold as Lumiblade and it is available online. The same goes for a Dresden based company, Novaled AG, which launched OLED desk lamps- Victory, in 2011.
The N85 and N86 phones by Nokia were one of the first to use the OLED display. But now, they are ubiquitous. Google and HTC Nexus One, Desire, Nexus S, LG phones, among others make use of the AMOLED technology.
Sony, LG, and Samsung are some of the major giants in the industry pushing the use of OLED in television sets.
The OLED technology is also used in the fashion industry, the automotive sector, production of cameras, and video games.
OLED has come a long way and is expected to be the mainstream display technology, usurping LEDs and LCDs in the future. However, research is still required to address some of the drawbacks of the technology.