Behaviour of Electrons and Holes in Cuprous Oxide

Abstract

IT is a remarkable feature of electron conductivity that an insulating crystal becomes conducting so soon as one section of it is illuminated by active light. The same phenomenon was found both in the experiments of Kikoin and in our own investigation on multicrystalline cuprous oxide plates. At liquid air temperature the current between E and F (Fig. 1) increases a hundredfold if a small section, S₁ S₂, be illuminated. Thus not only have we a stream of electrons from the illuminated section to the anode, but necessarily a supplementary stream between the cathode and S₁ S₂ also; the latter must be ascribed to the movement of free holes in a fully occupied band of electron levels, which is equivalent to a stream of positive electrons.