Abstract: A display panel includes: a substrate; a light emitting unit located on the substrate; and one or more combinational structure layers located on a side of the light emitting unit away from the substrate, each of the combinational structure layers includes a first structure layer, a second structure layer and a third structure layer, a refractive index of the first structure layer is greater than a refractive index of the second structure layer, and the refractive index of the second structure layer is greater than a refractive index of the third structure layer.

Abstract: A display panel and a display apparatus. The display panel includes: a substrate; a light-emitting element disposed on the substrate; an encapsulation layer on a side of the light-emitting element away from the substrate, where the encapsulation layer includes a first inorganic film layer, a first auxiliary film layer and an organic film layer stacked on the light-emitting element, an absolute value of a difference between a refractive index of the first inorganic film layer and a refractive index of the first auxiliary film layer is less than or equal to 0.05, and an extinction coefficient of the first auxiliary film layer for visible light is less than an extinction coefficient of the first inorganic film layer for visible light.

Abstract: The organic electroluminescent device includes a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, the organic layer includes a light-emitting layer, the light-emitting layer includes a host material, a thermally activated delayed fluorescence sensitizer and a green fluorescent dye, the green fluorescent dye includes a structure as shown in formula I. A thermally activated sensitized fluorescence technique is used, and the green fluorescent dye of a specific structure in combination with the sensitizer and the host material is used, so as to achieve the effects of narrowing the spectrum of a device and improving the green color purity. The efficiency of the organic electroluminescent device is equivalent to that of a phosphorescent green light device, so that a display panel including the organic electroluminescent device has a large display color gamut area.