A In-Ga-Se film with thickness of 100 nm is evaporated onto Mo layer prior to NaF deposition to improve the adhesion of Cu(In,Ga)Se2(CIGS) thin film on polyimide(PI) substrates.Compared with the traditional NaF precursor process, CIGS thin films on PI have superior adhesion, displaying less delamination by the new Na-incorporation process with the IGS-NaF-CIGS sequence, and have no significant degeneration in material and device properties.NaInSe2 is found in CIGS films and hence the In-Se vestige is reduce...