Scientists found excitons in nickel oxide for the first timeRussian scientists from Ural Federal Uni
Scientists found excitons in nickel oxide for the first timeRussian scientists from Ural Federal University (UrFU), together with their colleagues from Institute of Metal Physics of the Ural Department of Russian Academy of Sciences, have studied fundamental characteristics of nickel oxide nanocrystals and found excitons on the light absorption edge for the first time. An exciton is an electron-hole pair bound with electrostatic coupling that migrates in a crystal and transmits energy within it. The presence of an exciton in this area allows for detailed research of edge parameters in permitted energy bands. This may be useful for the development of next-generation optoelectronic devices. The results of the study were published in Physica B: Physics of Condensed Matter journal.Liquids and (under certain circumstances) gases are divided into conductors and dielectrics. The former conduct electricity, and the latter, respectively, do not. Semiconductors fall between these two categories—conductivity occurs due to the movement of charged electrons and holes within the crystal. They are found in systems with impurities that can either release or receive electrons, as well as after irradiation with high-energy light.“In the physics of semiconductors, there is a notion of fundamental adsorption edge that indicated the edge-level energy of light adsorption. It corresponds to the energy gap—the area of energies an electron has to pass in the course of movement under the influence of light from the valence band (where it is usually located) to the conductivity band. A positively charged empty space that occurs at this place is called a hole. Its electrostatic (Coulombic) interaction with the electron in the conduction band causes the formation of an electron-hole pair, or and exciton. In the optic spectrum it can be seen as a narrow line a little below the fundamental adsorption edge. Notably, an exciton does not participate in electrical conductivity, but transfers the absorbed energy,” says Anatoly Zatsepin, a co-author of the article, and the head of a scientific lab at UrFU.Read more. -- source link
#materials science#science#excitons#nickel oxide#nickel#oxides#nanocrystals#nanotechnology