Facile Ultrasound-Assisted Synthesis of Copper Zinc Tin Sulfide Chalcogenide Nanoparticles for Thin Film Solar Cell Applications

Single-step ultrasound-assisted synthesis of Copper Zinc Tin Sulfide nanoparticles (CZTS) has been studied at two different frequencies. While the effects of frequency on the particle size of the CZTS nanoparticles were insignificant, a noticeable change was observed in composition. As-obtained particles presented the amorphous nature and spherical morphology with a high degree of agglomeration. Annealing of the synthesized CZTS nanoparticles increased the crystallinity while the sulfur content decreased considerably. The poly-dispersity and agglomeration of the nanoparticles increased upon annealing. The as-obtained CZTS nanoparticles synthesized at 45 kHz frequency presented a copper deprived and zinc-rich composition suitable for higher photo-conversion efficiency of the solar cells. The bandgap of the annealed and non-annealed particles ranged between 1.25 eV and 1.65 eV.