Synthesis and Characterization of CuIn(S _x Se_1–x )₂ Nanocrystals

A series of nanocrystalline CuIn(S_xSe_1–x)₂ (x = 0.1, 0.25, 0.4) were one-step synthesized by solvothermal method at 220 °C for 10 hours. In this process, SC(NH₂)₂ was adopted as S source which can release active S^2– to mix with Se^2– in ethylenediamine solvent and result in less reaction time. Powder X-ray diffraction (XRD) pattern, transmission electron microscope (TEM) image and the electron diffraction pattern indicate that the chalcopyrite compounds of x = 0.25 is a pure tetragonal phase with an average diameter of 45 nm and the nature was single crystal. The composition of CuIn(S _x Se_1–x)₂ x = 0.25 nanoparticles investigated by energy dispersive spectroscopy (EDS) was Cu_1.25In_1.0S_0.54Se_1.47. Furthermore, the XRD patterns also reveal that phaseseparation phenomenon occurred when x = 0.4 for CuIn(S _x Se_1–x )₂ nanocrystals.