INVESTIGATION OF THE DEPOSITION PROCESS OF ULTRASONICALLY SPRAYED IN_2S_3 BUFFER LAYERS FOR CU(IN, GA)SE_2 THIN FILM SOLAR CELLS

摘要

Ultrasonic spray pyrolysis (USP) is a low-cost, non-vacuum and in-line compatible deposition method for alternative buffer layers such as indium sulfide in CIGS based thin-film solar cells. Solution precursors are ultrasonically atomized and transferred to a heated substrate. On the substrate's surface a thin layer is formed by a chemical reaction of the precursors. The layer formation is mainly influenced by the substrate temperature, the concentration of the precursor solution, the solvent properties and droplet feed rate. We present a possible chemical reaction equation and the mechanism for this reaction. CIGS based solar cells with USP-In_2S_3 buffer layer were fabricated and yielded reproducible efficiencies of 13% and best cell efficiency of 13.4% without anti reflection coating.