Oberflächenleitung und Oberflächenrekombination an der Grenze Silicium-Elektrolyt

Abstract

Measurements of surface conductivity and surface recombination on silicon samples contacted by different elctrolytes are reported. From these observations the following conclusions can be drawn: 1. The surface conductivity can be measured without noticeable disturbance due to the electrolyte. 2. A voltage applied between silicon and electrolyte forms accumulation and exhaustion layers at the silicon surface, but no inversion layers. Instead of them depletion layers are formed in which the concentration of both electrons and holes are reduced (non-equilibrium). 3. It is possible that the barrier layer completely takes over a variation ΔU El of the applied voltage. Especially in the exhaustion region the surface potential follows ΔU El exactly. 4. Very thin oxide layers already take over part of the applied voltage ΔU El . For small voltages it is proportional to U El , for large voltages it is constant. 5. The measurements of surface recombination on n-type silicon point to an acceptor-type recombination centre about.1 eV above the middle of the band gap.