OLED Displays

What is an OLED Display?

An OLED (organic light-emitting diode), also known as an organic electroluminescent diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current.

OLEDs are used to create digital displays in devices such as television screens, computer monitors, portable systems such as smartphones, and handheld game consoles.

An OLED display can be driven with a passive-matrix (PMOLED) or active-matrix (AMOLED) control scheme. In the PMOLED scheme, each row (and line) in the display is controlled sequentially, one by one. An AMOLED control uses a thin-film transistor backplane to directly access and switch each individual pixel on or off. This allows for higher density or resolution and also for larger display sizes.

Although its name looks similar, the OLED is fundamentally different from its cousin the LED. The LED is based on a p-n diode structure. In a LED, doping is used to create p- and n- regions by changing the conductivity of the host semiconductor. The OLED is not a p-n structure. Doping of OLEDs is used to increase radiative efficiency by direct modification of the quantum-mechanical optical recombination rate. Doping is additionally used to determine the wavelength of photon emission.

Similar to an LED, an OLED display works without a backlight because it emits visible light. This means that it can display deeper black levels, and it can be manufactured to be thinner and lighter than LCD panels.

OLED Panel Construction: