Conduction in Non-crystalline Materials III. Localized States in a Pseudogap and Near Extremities of Conduction and Valence Bands

World Scientific Series in 20th Century PhysicsSir Nevill Mott – 65 Years in Physics, pp. 465-482 (1995) No AccessConduction in Non-crystalline Materials III. Localized States in a Pseudogap and Near Extremities of Conduction and Valence BandsN. F. MOTTN. F. MOTTCavendish Laboratory, Cambridge, UKhttps://doi.org/10.1142/9789812794086_0027Cited by:1 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: If the distance between atoms in a crystalline lattice is increased, an energy gap appears, which in a divalent material will separate occupied from unoccupied states of an electron. In a non-crystalline substance, a minimum is expected in the density of states (a ' pseudogap '). An approximate theoretical estimate is given of the depth of the minimum at which the one-electron states become localized so that 〈σE(0)〉 vanishes ; this turns out to be such that N(EF)/N(EF)free is about . The result depends rather sensitively on the parameters used ; the value deduced from the experiments of Hensel and Franck (1966, 1968) on the resistivity of mercury at high temperatures gives for this ratio a value of . It is shown also that the localized states at the extremities of a valence or conduction band are of negligible importance if the wave functions are s-like on the atoms or ions, but may be of importance if they are not. A discussion is given of the electrical behaviour of chalcogenide glasses, amorphous germanium and of some liquid semiconductors based on these ideas. FiguresReferencesRelatedDetailsCited By 1Investigation of Electrical conduction and Optical properties of amorphous Se88Zn10Bi2 Chalcogenide thin filmZubair Aslam, Aadil Rashid Lone, Mohd Shoab and M. Zulfequar1 Jan 2023 | Chemical Physics Letters, Vol. 18 Sir Nevill Mott – 65 Years in PhysicsMetrics History PDF download