EFFECT OF IMPURITIES ON ANODE, CATHODE, AND AC GALVANOLUMINESCENCE SPECTRA OF ALUMINUM

The anode, cathode, and a.c. spectra of galvanoluminescent aluminum were measured in 1% aqueous H3PO4, using 140 V, 110 V, and 128 V respectively. Aluminum of technical purity, zone-refined aluminum, and zone-refined aluminum doped with single elements were studied; the impurities were Mn, Cr, Cu, Fe, Zn, Mg, and Nd. The spectra for anode and a.c. luminescence appear to be characteristic of these impurities, indicating that these phenomena are electroluminescence in the impurity-activated amorphous Al2O3 layer on the aluminum surface. The spectra of the cathode luminescence are essentially independent of the impurities, indicating that this phenomenon is probably not electroluminescence in the same sense. © 1969.