Thesis Abstract

Abstract
This research project focuses on the synthesis and optical characterization of nickel-doped zinc oxide (NiZnO) nanoparticles using the chemical bath deposition method. Zinc oxide nanoparticles have gained significant attention due to their unique optical and electrical properties, which make them promising candidates for various applications such as sensors, solar cells, and optoelectronic devices. Doping ZnO with transition metals like nickel can further enhance its properties and tailor its characteristics for specific applications. The chemical bath deposition method is a cost-effective and simple technique for synthesizing nanoparticles with controlled size and morphology. In this study, nickel-doped zinc oxide nanoparticles were prepared by adding nickel chloride to the chemical bath solution containing zinc nitrate and hexamethylenetetramine. The concentration of nickel dopant was varied to investigate its effect on the structural and optical properties of the synthesized nanoparticles. The structural characterization of the NiZnO nanoparticles was carried out using techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis revealed the formation of a hexagonal wurtzite structure characteristic of ZnO, with the presence of nickel dopant indicated by shifts in the diffraction peaks. SEM images showed the morphology of the nanoparticles and confirmed their uniform distribution. The optical properties of the synthesized nanoparticles were studied using UV-Vis spectroscopy and photoluminescence (PL) spectroscopy. UV-Vis spectra showed a redshift in the absorption edge of the NiZnO nanoparticles compared to pure ZnO, indicating the influence of nickel doping on the bandgap energy. PL spectra exhibited emission peaks corresponding to different defects in the nanoparticles, with the intensity and position of the peaks varying with the nickel concentration. Overall, this research provides valuable insights into the synthesis and optical characterization of nickel-doped zinc oxide nanoparticles using the chemical bath deposition method. The results demonstrate the tunability of the structural and optical properties of NiZnO nanoparticles through nickel doping, highlighting their potential for applications in various optoelectronic devices and sensors.

Thesis Overview

INTRODUCTION

1.1 GENERAL INTRODUCTION

Zinc oxide is an organic compound with formula ZnO it is a white powder that is insoluble in water. It is widely used as an additive into numerous materials and product including plastics, ceramic, glass, cement, rubber (e.g. car tire), lubricant, paint, ointment, adhesive, sealant, pigment, food, batteries etc. ZnO oxide is present in the earth crust as the mineral (Zinc cite), (Gonzalez, R. et al, 2008).

However, most zinc oxide (ZnO) nanoparticle can be prepared on a large scale at low cost by simple solution based method such as chemical bath deposition (CBD), chemical coprecipitation, Sol gel synthesis, spray pyrolysis pulse laser deposition and hydrothermal reaction etc (Zhong Q. P. etal, 1996).

Zno nanoparticles as an n-type semiconductor with a wide band gap (3.44eV) and large excitation binding energy (60 MeV), transition – metal doped ZnO is expected to play an important role in multidisciplinary area of materials science and future spintronic devices (Wolf S. A. et al; 2001).

Among the various methods to prepare ZnO nanoparticle, chemical bath deposition is an important method because the compounds will be dissolve in liquid and the microscopic slide also deposited in that same prepared solution. It does not require or depend on expensive equipment.

A semiconductor is a materials whose conductivity lies between that of a good conduction and a good insulator (Umoh, A. A; 2004). It properties also depends on dopant or impurities added to it. A n-type semiconductor carries current in the form of negative change while p-type carries current predominantly as electron deficiency called holes.

1.2 AIM AND OBJECTIVES

This study is aimed at modifying ZnO by doping it with nickel (Ni), a transition metal and the objectives are:

– To synthesis Ni-doped ZnO by chemical bath deposition (CBD) method.

– To characterized the sample to obtain it absorbance coefficient and band gab.

– To find the application(s) of the synthesis Ni-d-oped ZnO nanoparticle.

1.3 SCOPE OF THE STUDY

The scope of the study range from using chemical bath deposition (CBD) method of synthesis, to synthesized. ZnO an n-type semiconductor by doping it with transition metal of nickel to obtain zinc oxide nickel doped nanoparticle sample and using UV-vis method of characterization to obtained it absorption coefficient and the band gap of the sample and knowing the right application(s) of the characterized sample.