Display substrate and display device

A display substrate, comprising a light emitting element disposed on a base substrate, and a light dimming structure layer and an anti-reflection layer sequentially stacked at a light exiting side of the light emitting element,

• wherein the light dimming structure layer comprises a polarizing film layer configured to convert at least a portion of light which is emitted by the light emitting element and incident onto the polarizing film layer into circularly polarized light with a set rotational direction to pass through the polarizing film layer and a composite structure layer disposed at one side of the polarizing film layer facing the light emitting element, wherein the composite structure layer comprises a capping layer and an encapsulation layer;
• and
• the anti-reflection layer comprises a phase retarder and a linear polarizer which are stacked sequentially along a direction away from the base substrate, wherein the phase retarder is configured to convert the circularly polarized light passing through the polarizing film layer into linearly polarized light, a polarization direction of the linearly polarized light is parallel to a direction of a light transmission axis of the linear polarizer,
• wherein the polarizing film layer comprises a cholesteric liquid crystal layer, and the cholesteric liquid crystal layer and the light emitting element satisfy |Ne−No|×P≥FWHM×2 and |(No+Ne)×P−2λ|≤3×FWHM,
• wherein No is a refractive index of cholesteric liquid crystal parallel to an optical axis direction;
• Ne is a refractive index of the cholesteric liquid crystal perpendicular to the optical axis direction;
• P is a pitch of the cholesteric liquid crystal;
• λ is the peak wavelength of the emission spectrum of the light emitting element;
• and
• FWHM is a peak width at half height of an emission spectrum of the light emitting element.