1. The photovoltaically active zone includes an organic electron-donor material and an organic electron- acceptor material.

2. The organic composite layer is composed of an electron donor material, an electron acceptor material, and a polymer matrix material.

3. The photoconductive materials (950) include a first continuous layer of donor material (152) and a second continuous layer of acceptor material (154).

4. The present invention relates to the use of dibenzotetraphenylperiflanthene of formula (I) as an electron donor material in an organic solar cell comprising photoactive donor-acceptor transitions in the form of a bulk heterojunction.

5. In this manner, the present invention enables the manufacture of a memory device produced with a crystal layer formed in the organic layer and including donor material and acceptor material, to increase the electric charge probability of the nanocrystals and to improve the reliability of the device.