Capture of carriers to screened charged centres and low temperature shallow impurity electric field break down in semiconductors

Free carrier capture by a screened Coulomb potential in semiconductors are considered. It is established that with decreasing screening radius the capture cross section decreases drastically, and it goes to zero when $$. On the basis of this result a new mechanism of shallow impurity electric field break down in semiconductors is suggested.Comment: 8 pages, latex, 1 figure in gif format, to be submitted to "Journal of Condensed Matter

PRODUCTION OF Ge1-xLnxS MONOCRYSTALS AND THEIR ELECTROPHYSICAL AND PHOTOELETRIC PROPERTIES

Among semiconductor materials wich can be citilized for recording optical information and holograms of considerable interest are layered materials.Inparticulas, GeSmonocrystals belong to them. A unique device of germanium sulphide that can contain a great quantity of lithium ionehaz been created recently of the University North Carolina. Such material is perfectly suitable as starting stock in manufacturing solar panels. Along with these properties germaniummonosulphideposseffes change-over and memory effects. To widen the scope of using GeSmonocrystal it was introduced into the matrix of atoms of rare-earth elements (Nd,Sm,Gd). The present research explores the formation of Ge1-xLnxS (where Ln-Nd.Sm,Gd) monocrystals and studies their electrophysical and photoelectrical properties

Polaron Energy Spectrum in Quantum Dots

Energy spectrum of a weak coupling polaron is considered in a cylindrical quantum dot. An analytical expression for the polaron energy shift is obtained using a modified pertubation theory.Comment: 7 pages, IOP style LaTeX fil

Modification of cytogenetic and physiological effects of space flight factors by biologically active compounds

Physiological and cytogenetic changes in the Welsh onion plants induced by a short (82 days) and long term (522 days) space flight are expressed in decrease of seed germination, inhibition of stem growth, depression of cell division in root meristem, and increase in the number of structural chromosome rearrangements. The treatment of such plants with solutions of a-tocopherol, auxin, and kinetin decreased the level of chromosome aberrations to the control one and normalized cell divisions and growth partly or completely