The present disclosure relates to a flat panel display device and a top organic light emitting diode (Top-OLED). The Top-OLED includes: a light emitting unit and a light output coupling unit configured on a light output surface of the light emitting unit, wherein the light output coupling unit is configured with a first light emitting coupling layer and a second first light emitting coupling layer configured on the light output surface of the light emitting unit in sequence A refractive index of the first light emitting coupling layer is greater than a refractive index of the second light emitting coupling layer. The light emitting coupling layers configured on the light output surface of the light emitting unit having the refractive index being configured to be decreased gradually, so as to enhance the external quantum efficiency and to increase the amount of outputting light beams.