Molybdenum, commonly used as the back-contact material in CIGS solar cells, has been the subject of an in-depth study by sputtering target manufacturer Plansee, working in collaboration with TU Bergakademie Freiberg. Plansee’s results, presented at the ICMCTF Conference, identified the process errors and defect types present in molybdenum thin films that can have a detrimental effect on electrical conductivity.