Synthesis of Cu2ZnSnS4 nanocrystals and its third-order nonlinear optical properties

Abstract

Monodisperse Cu2ZnSnS4 (CZTS) nanocrystals were synthesized by one-pot method using copper (II) acetylacetonate, zinc (II) acetate, tin (II) chloride, S powder and oleylamine as precursors. The composition, structure, morphology and properties of the CZTS were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis and Z-scan technology. The results showed that the as-prepared CZTS nanocrystals were tetragonal phase with hexagonal shape and particle size about 10 nm. The nonlinear refraction index γ (-1.08 × 10-15, -9.08 × 10-17 m2 • W-1), nonlinear absorption coefficient β (6.5 × 10-9, 3.69 × 10-11 m • W-1) and third-order optical susceptibility χ(3) (1.49 × 10-9, 4.35 × 10-10 esu) of CZTS nanocrystals with different size (10 nm, 13 nm) were calculated. Finally, the growth mechanism of nanocrystals and the nonlinear optical properties were investigated.