Synthesis and characterization of LiNbO3 nanocrystals prepared by the aerosol assisted chemical vapor deposition method

This work reports the synthesis of LiNbO3 nanocrystals by an aerosol assisted chemical vapor deposition method, onto silicon (0 0 1) substrates. Some of the nanocrystals showed a hexagonal morphology and characteristic sizes ranging from a few tens to a few hundreds of nanometers. The nanocrystals with hexagonal structure were obtained at 773 K using a carrier gas flow of 6 L/min and a deposition time of 90 min. Structural, morphological, photoluminescence and cathodoluminescence properties were studied by grazing incidence X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, fluorospectrometry, and cathodoluminescence, respectively. An extraordinary violet luminescence at 396 nm with excitation in UV region (280 nm) was observed in one of the samples. Cathodoluminescence (CL) imaging and spectroscopy studies of the nanocrystals exhibit stimulated emission of light in the near ultraviolet-violet-green spectral region. The emission peaks in CL spectra varied according to the nature of nanoparticles. A red-shift in the CL spectra with a decrease in the particle size was observed. Apparently the size of LiNbO3 typical nanocrystals investigated in this work has tuned the photoluminescence emission. This result encourages the use and integration of LiNbO3 nanocrystals into nanophotonics applications.