The influence of adsorbate on the work function and penetrability of the surface potential barrier of GaAs(110) single crystal

The characteristic features of variations in the current-voltage characteristics of the current of slow monoenergetic electrons, which are introduced into single-crystal GaAs(110) from vacuum, were established with the removal of the native oxide layer from the surface. It is demonstrated that the work function decreases and the penetrability of the potential barrier increases with the temperature of thermal treatment of the crystal in high vacuum. The oxide removal was monitored simultaneously by ellipsometry. According to calculations from the Drude equations, the thickness of the removed layer is no larger than 20 Angstrom. (C) 2002 MAIK "Nauka / Interperiodica".