Modification of the crystal lattice and optical band gap of ZnO nanostructures by the polyelectrolytes presence

• Published in: Journal of materials science. Materials in electronics Vol. 29; no. 18; pp. 15604 - 15612
• Main Authors: Flores-Moreno, A., Herrera-González, Ana M., García-Serrano, J.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2018; Springer Nature B.V
• Subjects: Band gap; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Crystal lattices; Crystal structure; Crystallinity; Diffuse reflectance spectroscopy; Energy gap; Energy transmission; Kubelka-Munk equations; Materials Science; Nanoparticles; Nanorods; Nanostructure; Optical and Electronic Materials; Parameters; Photonic band gaps; Photonics; Polyelectrolytes; Polyvinylpyrrolidone; Spectrum analysis; Transmission electron microscopy; X-ray diffraction; Zinc oxide; Zinc oxides
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9152-7

Zinc oxide (ZnO) is a group II–VI semiconductor, with electronic and photonic importance due to its wide band gap (3.37 eV) and its high exciton energy of 60 meV. In this work we study the influence of poly( p -acryloylaminophenylarsonic acid) [Poly( p -AAPHA)], poly( o -acryloylaminophenylarsonic acid) [Poly( o -AAPHA)], and polyvinylpyrrolidone (PVP) on the crystalline lattice and optical band gap of ZnO nanostructures. ZnO nanoparticles were synthesized by Ge’s method, using the polymers as stabilizing agents. Subsequently, ZnO nanoparticles were subjected to solvothermal treatment for 48 and 96 h to form nanorods of ZnO. The samples were characterized by the following methods: X-ray diffraction (XRD), diffuse reflectance spectroscopy, transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). It was determined from XRD results that the crystalline lattice of ZnO can be contracted diminishing its c parameter in the bulk of 5.20 Å. Using Poly( p -AAPHA) and Poly( o -AAPHA) the new values are 5.15 and 5.16 Å, respectively. On the other hand, the use of PVP causes a lattice expansion reaching 5.25 Å for c parameter. The energy of the optical band gap calculated by Kubelka–Munk function was 3.22, 3.22, and 3.33 eV for ZnO nanoparticles in presence of Poly( p -AAPHA), Poly( o -AAPHA), and PVP, respectively. TEM images revealed an average size particle of 13, 14, and 17 nm for ZnO nanoparticles with Poly( p -AAPHA), PVP, and Poly( o -AAPHA), respectively. The average diameters of the ZnO nanorods were 11, 14, and 37 nm in presence of Poly( p -AAPHA), PVP, and Poly( o -AAPHA), respectively.