The present disclosure relates to an array substrate, a display device, and a method for fabricating an array substrate. The array substrate includes a pixel defining layer on the dielectric layer, the pixel defining layer defining a plurality of pixel regions of the array substrate, and light emitting device on the dielectric layer and in the plurality of pixel regions. The device includes a first electrode, a light emitting layer, and a second electrode sequentially disposed from bottom to top. At least one of the plurality of pixel regions has a non-light emitting region adjacent to the pixel defining layer. The dielectric layer in the non-light emitting region has a groove. The array substrate further includes a light shielding portion located in the non-light emitting region and extending into the groove.