Display panel and display device

A display device comprising:

• a display panel comprising:
• a first substrate;
• a second substrate disposed opposite to the first substrate;
• a waveguide layer disposed on a surface of the first substrate facing the second substrate for coupling incident light into the waveguide layer;
• a first electrode layer disposed on the waveguide layer, the first electrode layer comprising a plurality of first electrodes that are independently controllable;
• a second electrode layer disposed on a surface of the second substrate facing the first substrate;
• and
• a light emission control layer disposed between the first electrode layer and the second electrode layer, the light emission control layer defining a plurality of sub-pixels arranged in an array,
• wherein the light emission control layer is configured to control respective amounts of light to be coupled out of the waveguide layer to respective ones of the plurality of sub-pixels based on respective voltages applied between the plurality of first electrodes and the second electrode layer,
• wherein the light emission control layer comprises:
• an insulating layer on a surface of the first electrode layer facing the second substrate;
• an oily medium between the insulating layer and the second electrode layer, the oily medium being distributed in the plurality of sub-pixels;
• and
• an aqueous medium between the insulating layer and the second electrode layer, the aqueous medium being distributed in the plurality of sub-pixels,
• wherein the light emission control layer further comprises a grating layer disposed on a surface of the insulating layer facing the second substrate, and wherein the grating layer comprises gaps formed periodically to allow the oily medium and the aqueous medium to be in contact with the insulating layer.