Abstract

Abstract:
In this research thin films of (ZnS) have been prepared as pure and doped by Aluminum (Al), Copper (Cu) and Nickel (Ni) with different ratio (i.e 2% , 5%), the films were prepared by chemical spray Pyrolysis from zinc chloride (ZnCl2) and thioriaa (CS(NH2)2) at substrate temperature (583K). The structural properties of thin films were studied by using reflective optical microscope and x-ray diffraction. Were appeared that the thin films have polycrystalline structure type (Zincblende) and the doping processes did show obvious effect on crystal structure of (ZnS) films doping with (Cu and Ni) where became near from amorphous structure, also calculated the lattice constant (a) and its values decreased after doping process. From studying of optical properties for range of wave length (300-900nm), the transmission were (75-85%), where doping process did show decreases in transmission of thin films because extinction increasing in radiation intensity after doping. Also calculated the optical constant such as absorption coefficient (), extinction coefficient (K) and energy gap (Eg) for direct electronic transitions where value equal to (3.42eV) before doping and between (3.38-3.02)eV after doping depending on material and concentration doping. Finally, the electrical properties for all films were studied through variation of resistively () with temperature for range (303-413)K and calculated the electrical conductivity () and activation energy (Ea). As a result of the doping process the conductivity was increased but the activation energy was decreased, from Seebeck effect investigations showed all films were of (n – type), and from the measurements of the activation energy of electro-thermal power (Es) that the its values was increased after doping and from it calculated the activation energy of mobility (E) where equal to different between (Ea) and (Es).