Display panel, brightness compensation method and displaying device

A display panel, comprising:

• an array substrate;
• a luminescent layer located on one side of the array substrate, wherein the array substrate is configured for driving the luminescent layer to emit light;
• a plurality of optical film layers located on a side, away from the array substrate, of the luminescent layer, wherein light emitted by the luminescent layer forms an optical waveguide on the array substrate and/or the optical film layers;
• and
• a photoelectric sensor, configured for acquiring the optical waveguide to perform compensation of brightness on the light emitted by the luminescent layer according to data of the optical waveguide,
• wherein the luminescent layer comprises a plurality of sub-luminescent layers, the plurality of sub-luminescent layers are disposed on a same layer at intervals, the array substrate comprises:
• a first pixel defining layer located between two adjacent said sub-luminescent layers, the photoelectric sensor is disposed corresponding to the first pixel defining layer, the luminescent layer further comprises a first reflecting layer attached to a surface of the first pixel defining layer, and the optical waveguide passes through the first pixel defining layer and is reflected by the first reflecting layer to the photoelectric sensor.