Method of manufacturing high density CIS thin film for solar cell and method of manufacturing thin film solar cell using the same

A method of manufacturing a high density CIS thin film, comprising:

• preparing CIS nanoparticles;
• dispersing the CIS nanoparticles and dissolving a binder in a solvent to prepare CIS slurry;
• dissolving a filling element-containing salt and a binder in a solvent to prepare a filling element-containing slurry, wherein the filling element-containing salt is a mixed salt of at least two selected from the group consisting of copper salt, indium salt, gallium salt, zinc salt, and tin salt;
• mixing the CIS slurry and the filling element-containing slurry to prepare a slurry mixture;
• and
• coating the slurry mixture onto a substrate to form a CIS thin film, followed by heat treatment.