Synthesis, characterization and investigation of linear and infra-red nonlinear optical properties of TiO 2 /ZnO core/sh
- PDF / 4,138,429 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 16 Downloads / 179 Views
Synthesis, characterization and investigation of linear and infra‑red nonlinear optical properties of TiO2/ZnO core/shell nanospheres Azadeh Haghighatzadeh1 · Babak Mazinani2 Received: 10 September 2019 / Accepted: 29 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Titanium dioxide nanoparticles have been synthesized by the chemical co-precipitation technique and then they have been coated with zinc oxide shell layers using a refluxing method to form T iO2/ZnO core/shell nanoheterojunctions. The physicochemical properties of as-synthesized core/shell nanoheterojunctions have been examined using X-ray diffraction (XRD), Fourier transfer infra-red spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Photoluminescence (PL) emission spectroscopy has been carried out to analyze the linear optical characteristics at an excitation wavelength of 270 nm. A red shift towards longer wavelengths has been detected in NBE-related energies of T iO2/ZnO core/shell nanoheterojunctions compared to the sole TiO2 nanostructures. Third-order nonlinear optical studies have been performed by a single-beam Z-scan technique using a pulsed Nd-YVO4 laser system at a wavelength of 1064 nm. Third-order nonlinear refractive indices have been estimated as 10–12 m2/W. The sign of nonlinear refractive indices has been found to be negative, indicating self-defocusing behavior in the near infra-red region.
1 Introduction Nonlinear optical phenomena like optical chaos, optical bistability, multiphoton absorption and self-action effects have been found to be versatile probes in photonics, chemistry, material sciences and biosensing [1–6]. With the extensive application of nonlinear optics in various technological fields such as optical signal processing, optical computing, ultrafast switching, ultra-short pulsed lasers and laser amplifiers, much attention has been paid to the research on nonlinear optical materials [7–9]. Remarkable nonlinear optical features have been observed in crystals, amorphous materials, polymers, liquid crystals, organics, gases and plasmas [10]. Investigations on the metal-oxide semiconductor materials possessing large optical nonlinearities and fast response time have been an active area of research in recent decades [11]. With special emphasis on the arising unique features due to quantum confinement effects, nano-sized metal-oxide * Azadeh Haghighatzadeh [email protected] 1
Department of Physics, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
Department of Materials Engineering, Malayer University, Malayer, Iran
2
semiconductors have been considered to be a class of nanostructures potentially favored for optical nonlinearities [7]. In recent years, particular attention has been paid to nanostructured TiO2 semiconductors as a group of the most widely used materials in nonlinear-based technologies as they include superior optical nonlinear
Data Loading...
