Thesis Abstract

Abstract
In this study, nickel doped zinc oxide (NiZnO) nanoparticles were synthesized via the chemical bath deposition (CBD) method. The doping of nickel into the ZnO lattice was carried out to investigate its effects on the optical properties of ZnO nanoparticles. The structural and optical properties of the synthesized NiZnO nanoparticles were characterized using various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), UV-Vis spectroscopy, and photoluminescence (PL) spectroscopy. The XRD analysis confirmed the formation of wurtzite structure of NiZnO nanoparticles with good crystallinity. SEM images revealed the morphology of the nanoparticles with uniform distribution. The EDX analysis confirmed the presence of nickel in the ZnO lattice. UV-Vis spectroscopy showed a redshift in the absorption edge of NiZnO nanoparticles compared to pure ZnO, indicating the successful doping of nickel. The bandgap energy of NiZnO nanoparticles was calculated using Tauc plot analysis. Photoluminescence spectroscopy was used to study the optical properties of the NiZnO nanoparticles. The PL spectra exhibited a strong UV emission peak around 380 nm, attributed to the near-band-edge emission of ZnO. Additionally, the introduction of nickel into the ZnO lattice led to changes in the defect-related emission peaks, indicating alterations in the electronic band structure of the nanoparticles due to nickel doping. Overall, the results suggest that the chemical bath deposition method is an effective technique for synthesizing NiZnO nanoparticles with controlled optical properties. The doping of nickel into the ZnO lattice influences the structural and optical characteristics of the nanoparticles, making them suitable for various optoelectronic applications. Further investigations could focus on optimizing the doping concentration of nickel to enhance specific optical properties of NiZnO nanoparticles for targeted applications in sensors, photodetectors, and photocatalysis.

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.