The present invention concerns photoelectronic and/or optoelectronic learning device and/or memory device. In an embodiment, the device is a dye- sensitized solar cell. The short circuit photocurrent density (Jsc) of the device, and wherein a degree of a Jsc drop, depends on how long the device is being illuminated. During a subsequent absence of illumination, Jsc of the device increases in a time dependent manner. Furthermore, said degree of Jsc drop depends on the number of cycles of successive illumination and absence of illumination. The device of the invention may be considered as a self-evolving hardware that translates learning into long lasting changes in electronic parameters, akin to the neuronal network in the human brain. The device of the invention mimics traits of intelligent learning through optical stimulus. Particularly, the device exhibits and memorizes variations in its electronic properties differently, depending on the duration and the repetition rate of previous light exposure.