The present disclosure provides a photoelectric sensor, an array substrate, a display panel and a display device. The photoelectric sensor is used for fingerprint recognition, and includes a first electrode layer, being lighttight. The photoelectric sensor further includes a first transparent electrode layer, disposed opposite to the first electrode layer and receiving incident light, and a light sensing layer, located between the first electrode layer and the first transparent electrode layer. The light sensing layer includes a plurality of nanocrystalline silicon particles with different particle sizes.