The photoelectret state is an electret produced by the removal of light from an illuminated photoconductor in an electric field.
It was discovered by Georgi Nadjakov and the photoelectret state was essential to modern photocopying. He made a electret with light and electricity. The new electret was called photo-electret. The previous type of electret, obtained by heat and electricity, were called by him thermoelectret.
Photocopying is a partial list of text and image duplicating processes used in business and government from the Industrial Revolution forward. Some are mechanical and some are chemical. There is naturally some overlap with printing processes and photographic processes, but the challenge of precisely duplicating business letters, forms, contracts, and other paperwork prompted some unique solutions.
Without Georgi Nadjakov’s discovery we wouldn’t be able to use the photocopy machine the way we know it today.
- “Georgi Nadjakov, SUR UNE NOUVELLE ESPECE DE POLARISATION PERMANENTE DES DIELECTRIQUES”. Comptes Rendus de l’Académie des Sciences de Paris. 204: 1865–1866. 1937.
- “G. Nadjakov, UBER EINE NEUE ART VON ELEKTRETEN: PHOTOELEKTRETEN”. Physikalische Zeitschrift. 39 (6): 226–227. 1938.
- “Photoelectret State of Matter”.
- Kao, Kwan-Chi (2004). “5: Electrets”. Dielectric Phenomena in Solids. Academic Press. p. 283. ISBN 978-0123965615. Retrieved 12 November 2013.
- Encyclopedia2 photoelectret