Color filter substrate, display panel and display apparatus

A color filter substrate, comprising a photoluminescent layer and an optical path adjustment layer;

• the photoluminescent layer including a plurality of photoluminescent portions, and each photoluminescent portion being configured to receive backlight and emit excitation light;
• and
• the optical path adjustment layer being located on a light incident side of the photoluminescent layer, and the optical path adjustment layer being configured to increase an incident angle of at least portion of the backlight that enters the photoluminescent layer;
• wherein
• the photoluminescent layer has a plurality of backlight through holes arranged in an array, and the plurality of backlight through holes are arranged in parallel with the plurality of photoluminescent portions;
• the optical path adjustment layer includes a grating layer and a light-transmitting planarization layer, and the grating layer includes a plurality of gratings arranged in an array;
• the photoluminescent layer further includes a refractive index matching portion filled in each backlight through hole, and a light incident surface of the refractive index matching portion is attached to a light exit surface of at least one of the plurality of gratings;
• and
• a refractive index of the refractive index matching portion is less than a refractive index of the grating layer, and is greater than a refractive index of the light-transmitting planarization layer.