Elucidation of morphological and optoelectronic properties of highly crystalline chalcopyrite (CuInSe2) nanoparticles synthesized via hot injection route

CuInSe2 (CIS) nanoparticles have been prepared by the hot-injection method with sizes similar to 25 nm, and the thermal annealing influence on the size, morphology and optoelectronic properties of crystalline CuInSe2 nanoparticles has been elucidated. Microstructural analysis of synthesized nanoparticles was performed by various characterization methods including high-resolution transmission electron microscopy (HR-TEM), Scanning TEM (STEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The fast Fourier transform (FFT) pattern of HR-TEM image of annealed CuInSe2 nanoparticles illustrates that the particles have quasi-single crystal tetragonal structure, as also confirmed by the XRD pattern. The HR-TEM image clearly shows the fringe widths are in order without any defect with 0.32 nm. Microstructural analysis results clearly indicate that the synthesized and air-annealed nanoparticles are in highly crystalline state with near stoichiometric atomic composition.