Experimental and numerical results in hydrothermal synthesis of CuInS2 compound semiconductor nanocrystals

Nanocrystals of CuInS2 ternary chalcogenide semiconductors were prepared by a one-step synthesis and crystallization method using the hydrothermal technique. Different precursors (CuCl2, CuCl-as Cu sources; In metal as In source, CS2, S powder-as S sources), different autoclaving conditions (filling rate: 80-90%; temperature: 150-250 degrees C; reaction time: 5-90 h) and water as solvent were used. The precipitated products were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). XRD spectra reveal the presence of tetragonal chalcopyrite CuInS2, in some conditions single-phase samples are obtained. Electron microscopy images indicate that the particles are nanosized, having different morphologies, with dimensions ranging from 5 to 100 nm. The presence of aggregated "secondary particles" is also observed in the SEM images. Finally, the formation of nanocrystals in homogeneous and inhomogeneous thermal fields was studied. FLUENT (TM) software was used for the simulation of inhomogeneous global thermal field. (C) 2004 Elsevier B. V. All rights reserved.