G. S. Nadshakov was the first to suggest the usage of the depolarization electricity to be used in the study of the electretic load. To achieve this he uses innovative highly sensitive electrometric methodology. An important aspect of G. S. Nadshakov’s discovery is the fact that the dark photoelectric polarization is preserved for days. The notable Bulgarian physicist clearly distinguishes the photoelectric state and the ordinary photo polarization in photoconductors.

       Later, the infamous scientist forms his ingenious proposal regarding the possibilities of creating a photoelectetic condition under the action fo ionized emissions which was later confirmed.

       The second period in which the interest of G. S. Nadshakov again was directed towards the studies of the photoelectretic state was associated with his work after 1955. In the world literature in this period it is observed a dramatic increase of the publications that are somehow connected with the phenomenon mentioned. His students A.Antonov, N. Kashukeev, and St. Balatanov also work on studies in this field.

       Leading factors for the increase of the interest towards the photoelectrets in world scale are the discovered possibilities for practical application of the studies phenomenon. For the first time during the sixties the electrophotography over photoel;ectrets becomes reality. Their possibilities as information carriers are studied.

       G. S. Nadshakov’s interest towards the photoelectrets did not end during his lifetime. His studies of the photoelectretic state obtained under the action of x-rays, which are conducted in the solid body physics institute to BAS in the end of the sixtieth and the beginning of the seventieth are remarkable.