Mo effect on one-step sputtering chalcopyrite CIGS thin films

In this study, we have investigated the working pressure effect on the properties of molybdenum (Mo) films and how the Mo back contact affects the chalcopyrite Cu(In,Ga)Se₂ (CIGS) films, which are prepared by one-step sputtering process. The properties of surface morphology, crystalline structure and residual stress are discussed. Mo films sputtered at low working pressure have dense structure with compressive stress, and become porous with tensile stress at high working pressure. In addition, the preferred orientation of following deposited CIGS film shows strong correlation with the residual stress of Mo back contact.