Structural and optical properties of TiO₂–Ge nanoparticles prepared through laser ablation in liquid medium

Abstract

Quantum dot (QD) composite nanoparticles of titania germanium (TiO2–Ge) were fabricated by pulsed laser ablation of composite targets of TiO2–Ge immersed in deionized water. The single phase crystallanity, lattice parameters, and the evaluation of crystallite size of nanoparticles was investigated by X-ray diffraction (XRD). The morphology of the samples was analyzed through scanning electron microscopic studies. The average particle size calculated through XRD and measured through scanning electron microscope is in the range from 18 to 29 nm and are in agreement with each other. Compositional study was carried out through electron dispersive X-ray analysis showing that the ablation rate of Ge is smaller than TiO2. Optical properties were measured by UV–visible transmission spectra and Raman spectroscopy. The band gap of composite particles varies from the UV to the visible range by varying concentration of Ge QDs. This work shows that pulsed laser ablation in liquid media is an easy approach to synthesize ultrafine, contamination-free nanosized material, which is difficult to produce by other conventional methods.