Effect of Ni Doping on ZnO Nanorods Synthesized Using a Low-Temperature Chemical Bath THEMBINKOSI DONALD MALEVU , 1,6 BENARD SAMWEL MWANKEMWA , 2 MUSTAFA A.M. AHMED, 3 TSHWAFO ELIAS MOTAUNG, 4 KAMOHELO GEORGE TSHABALALA , 5 and RICHARD OPIO OCAYA 5 1.—School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa. 2.—Department of Physics, School of Physical Sciences, College of Natural and Mathematical Sciences, University of Dodoma, P.O. Box 338, Dodoma, Tanzania. 3.—Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, 11115 Omdurman, Sudan. 4.—Department of Chemistry, University of Zululand, KwaDlangezwa Campus, Private Bag X1001, KwaDlangezwa 3886, South Africa. 5.—Department of Physics, University of the Free State, Private Bag X13, Phuthaditjhaba 9866, South Africa. 6.—e-mail: Malevu.td@gmail.com The present study evaluates the effects of Ni doping of ZnO nanorods syn- thesized using the low-temperature chemical bath method. The article is motivated by the apparent variability in the literature which report con- trasting results on the effect of Ni doping of the ZnO host matrix. The choice of method was decided by the accepted belief of its high reproducibility and accuracy. The concentration of Ni in the ZnO nanostructure host matrix is varied from 0%, 5%, 7.5% and 10% Ni. The products were characterized using several standard techniques. The various results are found to reinforce each other and show that the presence of Ni enters the host matrix as Ni 2+ and alters the ZnO nanostructure dimensions and morphology significantly. This study provides direct spectroscopic evidence of the modification of the ZnO crystal structure by the incorporation of Ni. This article therefore provides much needed clarification of the mechanisms of local ZnO nanorod symmetry modification by Ni. Key words: ZnO nanorods, photoluminescence, Raman properties, XPS, low-temperature, chemical bath method INTRODUCTION Zinc oxide is an important group II–VI n-type semiconductor with a wide room temperature bandgap energy of 3.37 eV and a free excitonic binding energy of 60 meV. It crystallizes into nanostructures with different morphologies that can be controlled by low-cost synthesis conditions. Simple techniques like chemical bath deposition (CBD) and hydrothermal and co-precipitation meth- ods have been reported. 1 To date, ZnO nanorods, nanowires and nanotubes have been applied in electronic, opto-electronic and chemical sensors and devices. 2–7 Transition metal doping of ZnO:X (where X = Co, Mn, Fe, Cu or Ni) is also increasingly being attempted in the hope of enhancing the structural, optical, ferromagnetic and electrical properties of ZnO. 8 Ni 2+ is thought to be the most promising candidate due to its comparable ionic radius of 0.069 nm versus 0.074 nm for Zn 2+ . Several workers have investigated the effects of low concentration Ni doping on the optical, structural and electrical properties of sprayed ZnO films. There is significant variability in the literature results. Some results suggest that the presence of Ni alters structural and optical properties of the films 9–11 with a general (Received March 27, 2019; accepted July 26, 2019) Journal of ELECTRONIC MATERIALS https://doi.org/10.1007/s11664-019-07490-2 Ó 2019 The Minerals, Metals & Materials Society