An OLED consists of the following parts:

• Substrate (clear plastic, glass, foil) - The substrate supports the OLED.

• Anode (transparent) - The anode removes electrons (adds electron "holes") when a current flows through the device.

• Organic layers - These layers are made of organic molecules or polymers.
  • Conducting layer - This layer is made of organic plastic molecules that transport "holes" from the anode. One conducting polymer used in OLEDs is polyaniline.
  • Emissive layer - This layer is made of organic plastic molecules (different ones from the conducting layer) that transport electrons from the cathode; this is where light is made. One polymer used in the emissive layer is polyfluorene.

• Cathode (may or may not be transparent depending on the type of OLED) - The cathode injects electrons when a current flows through the device.