SURFACE STATES AND PESHEV’S ADSORBON

The basis of the effects being observed is the Shockley surface states on semiconductor surfaces of metallised superinsulation screens and their interaction with
acceptor and donor gases in the process of well-known Bardeen-Brettain-Shockley gas-water cycle [32, 33].

Generally the conditions of atom existence on the surface of solids differ from the conditions, in which they are in a volume. The surface states are characterised by a greater probability of electron staying near the surface. They have their own energy levels differing from the volume states. The appearance of Tamm’s surface states [35] can be explained by means of the strong bond method (LKAO). Shockley [36] and Maue [37] have found another type of surface states known as Shockley’s levels. These states arise when free valencies exist on the surface. The Shockley’s chemisorption states appear only in case of a weak interaction between the adsorbent and the solid. It is this state that is characteristic to the Bardeen-Brettain-Shockley gas-water cycle [32, 33].

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The hydrogen adsorption occurred on disperse surfaces of a dimension-quantised semiconductor film [6]. As the main model for the adsorbate placing on the adsorbent, the Peshev’s adsorbon can be successfully used. According to this model, the current carrier in the dimension-quantised film with an adsorbate consists of a conductivity electron (with x, y,z coordinates) and adsorbed molecules at the (y, z) surface section with the area of Л2. In the transverse direction, the electron is connected with the adsorbed molecules by an interaction depending only upon x, whereas along the у and z axes it moves freely changing its adsorption framing. It is assumed that the longitudinal and transverse movements of the carrier are separated, as it takes place in the film without an adsorbate. The difference is that the transverse part contains adsorbed molecules now and therefore determines the carrier mobility by its state. This state is just the Peshev’s adsorbon.