A quaternary Laves-type phase in Ag-Cu-In-Ga thin films

Formation of a new quaternary Laves-type phase in sputter-deposited and evaporated thin films of AgCu-In-Ga (ACIG) is reported. Films with different compositions are analyzed by energy dispersive x-ray spectroscopy and x-ray diffraction to determine composition and structure based on Rietveld whole pattern refinement. Annealing and partial reaction with H2Se are used to study the phase. The quaternary phase corresponds to (Cu1-xGax)(2)(AgyIn1-y) with x approximate to 0.2 and approximate to 03. It has a Cu2Mg-type crystal structure with space group of Fd (3) over barm and lattice parameter of 7.090. Finally, formation of this phase is reported in the composition range (Ag + Cu)/(In + Ga) approximate to 0.8-0.9 suitable for precursors to the formation of chalcopyrite thin films for photovoltaic application. (C) 2017 Elsevier B.V. All rights reserved.