Effect of molybdenum deposition temperature on the performance of CuIn1?xGaxSe2 Solar Cells

We have studied the effect of substrate temperature in molybdenum (Mo) back contact deposition on its structural evolution, optical properties, and most importantly, the over-deposited CuIn_1-xGa_xSe₂ solar cell performance. A series of Mo thin films was DC sputtered onto thermally oxidized Si at substrate temperatures from 25°C to 385°C. Real time spectroscopic ellipsometry (RTSE) was performed to determine the evolution of the bulk and surface roughness layer thicknesses as well as the complex dielectric functions of the Mo films. CuIn_1-xGa_xSe₂ solar cells were fabricated for comparison on Mo back contact films deposited on soda lime glass at 25°C and 250°C.