Electrical Properties of Magnesium Carbon Co-Sputtered Thin Films Applied Post Hydroxylation Treatment

Abstract

ABSTRACTIndium oxide doped with tin oxide, or ITO, has been widely used as an electrode material for flat panel displays. However, the rare metal in ITO is a limited natural resource. We succeeded in developing a material composed solely of elements with abundant reserves. We present the results of analyzing the electronic structure of an Mg-based compound based on its electrical conductivity. Mg-C thin films were prepared by sputtering method. A new transparent and electrically conductive material, Mg(OH)2-C, was formed after reacting the Mg-C film with moisture in air. On average, its transmittance of visible light was 90%. The mechanism for the effect of carbon on the electrical conductivity of Mg(OH)2 was examined on the basis of XPS spectra and DV-Xa molecular orbital calculations. The value of the band gap shows that Mg(OH)2 is an insulator. It was revealed that a new orbital appears when the number of substituting carbon atoms increases in the Mg(OH)2 lattice. It was possible to measure the new orbital that consisted of C-2s and C-2p. In addition, a comparison between the calculated electronic state around the valence band and the result measured by XPS of the obtained film reveals that they are in extremely close agreement.