Synthesis of chalcopyrite CuIn1−xGaxSe2 alloys for photovoltaic application by a novel melting method

CuIn1−xGaxSe2 (CIGS) compounds used for the fabrication of thin-film solar cell absorber layers have been synthesized by a novel melting method which is easily controlled and practical. Based on vapor phase transport caused by the temperature gradient built, the quaternary CIGS alloy was prepared from the low-cost elementary Cu, In, Ga and Se in a closed quartz tube at 1100 °C for 3 h. Through various characterization methods, the as-synthesized alloy with crystal grains sized 100-150 µm presented a desirable chemical composition and a single-phase chalcopyrite structure. Furthermore, the CIGS absorber layer made from this material turned out to be high-quality with a correct phase and large nanocrystals, indicating great application potential of the proposed method in low-cost solar cell fabrication.