Sol-gel synthesis and optical properties of CuGaS2 quantum dots embedded in sodium borosilicate glass

I-III-VI2 ternary semiconductor CuGaS2 quantum dots embedded in sodium borosilicate glass matrix were synthesized by combining the sol-gel process and heat treatment in H2S gas. The structure and morphology of the obtained glass were studied by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that tetragonal crystalline phase of CuGaS2 quantum dots with spherical shape were formed uniformly in the sodium borosilicate glass matrix, and the sizes ranged from 5 to 25 nm with an average particle size of 12.75 nm. The optical nonlinearity was studied using Z-scan technique employing 200 fs at the wavelength of 800 nm. The glass doped with CuGaS2 quantum dots exhibited large third-order optical nonlinear susceptibility χ(3) of 1.60 × 10−9 esu.