Cu/Cu/sub 2/O cells prepared by hydrogen bombardment

A new method for preparing Cu/Cu/sub 2/O cells involves bombardment of Cu/sub 2/O by a beam of hydrogen ions. The cells have V /SUB oc/ up to 0.72 V, compared with 0.35 V for cells made by thermal evaporation of Cu on Cu/sub 2/O. Auger studies show that the hydrogen bombardment reduces the top surface of the Cu/sub 2/O to Cu, creating the Cu/Cu/sub 2/O junction. The optimum processing conditions are bombardment at 250 V for 75s at 15 mA. The surface resistivity of the Cu film decreases with bombardment time, but 75s gives adequate continuity in the film. Electron diffraction shows the Cu is formed epitaxially on the Cu/sub 2/O. Encapsulated cells are relatively stable. The conversion efficiency has reached 1.3% for 1 cm/sup 2/ cells.