In this study, the effects of CuCl treatment process parameters on CdSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Te <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> /CdTe graded absorber photovoltaic devices were studied. A statistically designed experiment was conducted to determine the significance, magnitude, and interaction of several factors on the performance of the device. The device performance data were analyzed using JMP statistical software, and regression models and mathematical prediction expressions were generated. Two out of the eight CuCl processing conditions yielded devices of 19%+ efficiency, revealing new highly effective processing conditions for CuCl doping. Furthermore, the limits of the modeling methods were also explored.