Effect of maximum Cu ratio during three-stage CIGS growth documented by design of experiment

The impact of a Cu-rich growth period during three-stage CIGS co-evaporation on device performance was examined. Design of experiments was utilized to determine effect magnitudes and statistical significance. It was found that a Cu-rich growth period yields a statistically significant benefit for device performance. By varying film thickness, the number of moles deposited in stage 3 was also included as a variable. The latter did not produce a significant effect on efficiency. Comparison of these conclusions to other studies, and the application to manufacturing, are also discussed.