Cu(In,Ga)Se-2 thin films preparation from CuGa-In metallic alloy and Se thin film by atmosphere pressure plasma deposition system

Abstract

An atmosphere pressure plasma (APP) deposition system with dielectric barrier discharge (DBD) is proposed for deposition selenium thin films on CuGa-In metallic precursors and transformed into Cu(In,Ga)Se-2 (CIGS) thin films by rapid thermal process (RTP). Morphologies and thicknesses of selenium thin films deposited on In/CuGa/Mo/SLG can be affected by plasma power which also has impact on crystallinity of CIGS absorber. With the increase in plasma power, CIGS grains tend to distribute non-uniformly. Plasma power of 100W has the smallest FWHM of the main peak (112). Insufficient selenium incorporation into precursors result in undesired phases such as Cu3Se2, Cu2Se and separation phase, CuGaSe2 compound. Compositions of optimal selenized CIGS thin film deposited by scanning 180times are Cu/(In+Ga) = 1.03 and Ga/(In+Ga) = 0.24.