CHAPTER ONE

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.