OLED

Definition

An Organic Light-Emitting Diode (OLED) is an LED made with organic materials.

The diodes in displays made with OLEDs emit light when a voltage is applied to them. The pixel diodes are selectively turned on or off to form images on the screen. This kind of display can be brighter and more efficient than current LCD displays.

OLED technology uses organic (carbon-based) materials, instead of semiconductor (e.g., Silicon, Indium) materials used by standard LEDs. Each pixel of an OLED display comprises a red, green, and blue diode (Figure 1) which emit light when a voltage is applied to them. Each diode can be switched on and off in different combinations and with different intensities to illuminate pixels, which then combine to create images on a screen.

What is the Difference Between OLED and WLED?

WLED (white light emitting diode) is a term usually associated with television and mobile phone LCD displays. Although WLED is marketed as being in some way “different” or “superior” to standard LEDs, WLED and LED technology are identical using semiconductor materials. The white light produced is used as a ‘backlight’ for LCD displays and is created by applying an electric field to a blue (or UV) LED and then filtering the emitted light through a material of a different colour (e.g., a yellow phosphor). The combination of the light and filter create (almost) white light. In an LCD display, this light is then polarized using arrays of many liquid crystals, which operate under the influence of variable electric fields to create images on a screen.

What are the Relative Advantages and Disadvantages of OLED/WLED?

The main advantage of OLED technology is that it allows displays to be much thinner (up to 10x) than displays made using LCD technology (with WLED backlight). Another important advantage is that because OLED displays do not need a backlight, they consume less power. This is critical for battery-powered displays (e.g., smartphones) as it means the battery does need to be charged as often. However, some disadvantages of OLED displays are that they are less water-resistant and the colors they produce deteriorates over time.