Structural properties of CuInSe2 films prepared by selenization of metallic precursors on MoNx film substrates

The aim of this work was to study the effect of MoNx film substrates on the structural properties of CuInSe2 films prepared by selenization of metallic Cu-In alloy precursors. MoNx films were prepared by reactive dc-magnetron sputtering. All the CuInSe2 films exhibit single phase chalcopyrite structure with (1 1 2) preferred orientation, which can be explained by the reduction of lattice mismatch between CuInSe2 and MoNx. The bulk composition of selenized CuInSe2 films are near stoichiometric, but the surface composition analysis suggests Cu deficiency on surface area. Furthermore, ordered defect compound, CuIn2Se3.5 is found on the surface of CuInSe2 films. The results will be helpful for fabricating Cd-free ZnO buffer layer CuInSe2 and Cu(In1−xGax)Se2 based thin film solar cells.