Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

Cu2ZnSnS4 (CZTS) nanoparticles were synthesized by a solvothermal method using copper (II) acetate, zinc acetate, tin chloride, and sulfur in diethylenetriamine solvent. Binary sulfide particles such as CuS, ZnS, SnS, and SnS2 were obtained at 180°C; single-phase CZTS nanoparticles were obtained at 280°C. CZTS nanoparticles with spherical shape and grain size of 40 to 60 nm were obtained at 280°C. In the middle of 180 and 280℃, CZTS and ZnS phases were found. The time variation of reaction at 280°C revealed that an amorphous state formed first instead of binary phases and then the amorphous phase was converted to crystalline CZTS state; it is different reaction path way from conventional solid-state reaction path of which binary phases react to form CZTS. CZTS films deposited and annealed from single-phase nanoparticles showed porous microstructure and poor adhesion. This indicates that a combination of CZTS and other flux phase is necessary to have a dense film for device fabrication.