Phases in copper gallium metal sulfide films metal titanium, iron, or tin

The incorporation of metal impurities M M Ti, Fe, or Sn into CuGaS2 films is investigated experimentally as a function of impurity concentration. Films are synthesized by thermal co evaporation of the elements onto glass Mo substrates heated to 400 C 570 C. The compositions of the resulting films are measured by energy dispersive x ray spectroscopy and the structures of the present phases are studied by x ray diffraction. The formation of Cu M S ternary phases is observed in a wide range of conditions. Films of Cu Ga Ti S, synthesized at 500 C, show the presence of a cubic modification of CuGaS2 and Cu4TiS4. Alloying of CuGaS2 and tetragonal Cu2SnS3 is observed for substrate temperatures of 450 C. A miscibility gap opens at 500 C and above with separate Sn rich and Ga rich phases. Similarly, alloys of CuFeS2 and CuGaS2 are only found in Cu Ga Fe S films synthesized at lower substrate temperature 400 C , whereas at 500 C a miscibility gap opens leading to separate Fe rich and Ga rich phase