Effect of Stresses in Molybdenum Back Contact Film on Properties of CIGSS Absorber Layer

摘要

Analysis of CuIn_(1-x)Ga_xSe_(2-y)S_y (CIGSS) absorber and molybdenum back contact layer was carried out to understand the changes in the microstructure of CIGSS layer as a function of the deposition conditions and the nature of stress in the underlying Mo film. All the depositions were carried out on 10 cm x 10 cm glass substrates. Compressive and tensile stressed molybdenum films were prepared with combinations of deposition parameters; power and pressure. CIGSS absorber layer was prepared by depositing metallic precursors using DC magnetron sputtering followed by selenization and sulfurization. Molybdenum layer deposited at 300 W and 3x10~(-4) Torr pressure produced compressive stress with compact, well adherent and lower sheet resistance as compared to the tensile stressed film deposited at 200 W and 5 x 10~(-3) Torr. The crystallinity of the CIGSS film was found not to depend on the stress in the underlying molybdenum film. However, the adhesion at the Mo/CIGSS as well as gallium profile at the Mo/CIGSS interface were affected by the stress.