Light-emitting device

A light-emitting device, comprising a substrate layer and pixel isolation structures disposed on a first surface of the substrate layer, a plurality of sub-pixel regions isolated from each other being formed between the pixel isolation structures, and further comprising:

• a plurality of light-emitting units disposed one-to-one in each of the sub-pixel regions for emitting different wavelengths of light, the light-emitting units being electroluminescent devices, and an initial external quantum efficiency of each of the light-emitting units being different;
• a plurality of light extraction structures disposed one-to-one in at least part of the plurality of sub-pixel regions for increasing an external quantum efficiency of the corresponding light-emitting units and reducing deviations of an actual external quantum efficiency of each of the light-emitting units,
• defining the light-emitting unit with the highest initial external quantum efficiency as a first light-emitting unit, the light-emitting unit with the lowest initial external quantum efficiency as a third light-emitting unit, and the light-emitting unit with the initial external quantum efficiency being between the highest initial external quantum efficiency of the first light-emitting unit and the lowest initial external quantum efficiency of the third light-emitting unit as a second light-emitting unit;
• the plurality of light-emitting units and the plurality of light extraction structures being disposed in one-to-one correspondence, and an improvement ratio of the external quantum efficiency of the first light-emitting unit by the light extraction structure being X1, an improvement ratio of the external quantum efficiency of the second light-emitting unit by the light extraction structure being X2, an improvement ratio of the external quantum efficiency of the third light-emitting unit by the light extraction structure being X3, and the X1, the X2 and the X3 being not equal, defining XN=Q2−Q1/Q1, wherein, the n is any natural number from 1 to 3, the Q1 is the initial external quantum efficiency of the corresponding light-emitting unit, and the Q2 is the actual external quantum efficiency of the corresponding light-emitting unit.