An array substrate, comprising a plurality of pixel units arranged in an array, each pixel unit comprising a light emitting unit and a pixel definition layer disposed around the light emitting unit; wherein in at least one of the pixel units, a light wave partition groove is provided in the pixel definition layer on at least one side of the light emitting unit, and a light wave blocking layer is provided in the light wave partition groove; wherein the light wave blocking layer is made of a transparent material, the refractive index and reflectivity of the transparent material being different from those of a material of the pixel definition layer; wherein the light emitting unit is an organic light emitting diode, OLED, comprising an anode and a cathode disposed opposite to each other, and an OLED light emitting layer between the anode and the cathode; and the light wave blocking layer is an extension part of the cathode; wherein a planarization layer and/or a passivation layer is arranged on a side of the anode away from the cathode, characterised by the light wave partition groove extending into the planarization layer and/or the passivation layer, and an extension part of the light wave partition groove being an extension slot; wherein the array substrate comprises red pixel units, green pixel, blue pixel units and white pixel units (W, 6); a pixel unit group composed of a red pixel unit, a green pixel unit and a blue pixel unit is provided on each of two sides of each white pixel unit along a row direction of the pixel units or a column direction of the pixel units, and the white pixel unit is arranged to be adjacent to the red pixel unit, the green pixel unit, or the blue pixel unit of the pixel unit group; wherein at least one of the pixel units provided with the light wave partition groove is the red pixel unit adjacent to the white pixel unit; or at least one of the pixel units provided with the light wave partition groove is the green pixel unit adjacent to the white pixel unit; or at least one of the pixel units provided with the light wave partition groove is the blue pixel unit adjacent to the white pixel unit; and the light emitting unit in the white pixel unit is a white OLED. wherein the light emitting unit is an organic light emitting diode, OLED, comprising an anode and a cathode disposed opposite to each other, and an OLED light emitting layer between the anode and the cathode; and the light wave blocking layer is an extension part of the cathode; wherein a planarization layer and/or a passivation layer is arranged on a side of the anode away from the cathode, characterised by the light wave partition groove extending into the planarization layer and/or the passivation layer, and an extension part of the light wave partition groove being an extension slot; wherein the array substrate comprises red pixel units, green pixel, blue pixel units and white pixel units (W, 6); a pixel unit group composed of a red pixel unit, a green pixel unit and a blue pixel unit is provided on each of two sides of each white pixel unit along a row direction of the pixel units or a column direction of the pixel units, and the white pixel unit is arranged to be adjacent to the red pixel unit, the green pixel unit, or the blue pixel unit of the pixel unit group; wherein at least one of the pixel units provided with the light wave partition groove is the red pixel unit adjacent to the white pixel unit; or at least one of the pixel units provided with the light wave partition groove is the green pixel unit adjacent to the white pixel unit; or at least one of the pixel units provided with the light wave partition groove is the blue pixel unit adjacent to the white pixel unit; and the light emitting unit in the white pixel unit is a white OLED.