Light-emitting device and manufacturing method therefor, and display substrate

A light-emitting device, comprising:

• a first electrode, and a first carrier transport layer, a light-emitting layer, a second carrier transport layer and a second electrode that are stacked on the first electrode in sequence, wherein transmittance of the second electrode is higher than that of the first electrode, and the transmittance is transmittance of visible light;
• the first carrier transport layer includes at least two first carrier transport sub-layers with different refractive indexes, and in the at least two first carrier transport sub-layers, the refractive indexes of the first carrier transport sub-layers decrease layer by layer in a direction from the light-emitting layer to the first electrode;
• and in the at least two first carrier transport sub-layers, a thickness of a film layer with a low refractive index is greater than a thickness of a film layer with a high refractive index;
• and/or,
• the second carrier transport layer includes at least two second carrier transport sub-layers with different refractive indexes, and in the at least two second carrier transport sub-layers, the refractive indexes of the second carrier transport sub-layers decrease layer by layer in a direction from the light-emitting layer to the second electrode;
• and in the at least two second carrier transport sub-layers, a thickness of a film layer with a low refractive index is greater than a thickness of a film layer with a high refractive index.