The structural, optical and electrical properties of undoped and Ga doped ZnO compounds produced by chemical spray prolysis technique

In this work, ZnO semiconductor films are produced at 375±5°C substrate temperature by ultrasonic chemical spray pyrolysis technique. It is investigated the effect of Ga doped (20 – 40 – 60 – 80%) on the physical properties of ZnO films. It is seen that at in x – ray diffraction pattern.the structure of ZnO film is doping Ga 80% changed from hexagonal structure to orthorhombic structure. Calculated using x – ray diffraction patterns. The lattice constant (a), crystalline size (D) and dislocation density (d) values of undoper and Ga doped ZnO films are changed in intervals 3,1489 Å to 13,5370 Å, 10 nm to 36 nm and 0,77x10-3(nm)-2 to 1,19x10-3(nm)-2 respectively. The as a result of examining the oplicproperhesatthe undoped and Ga doped Zno semiconductor films, ıt is determined that have direct band transition. In order to determine the electrical conductivity and resistivity values of the films, hot probe and four probe techniqees were used, respectively. The resistivities valves are between 3,47x104 Ωm and 0,356x102 Ωm. From the Atomic Force Microskopy images of films, Rq (rms roughness) changed from 8.5 nm to 11.4 nm, Ra (average roughness) changed from 10.887nm to 14.404nm and Rpv (peak valley) changed from 71.7 nm to 91.8 nm. The thicknesses of undoped and Ga doped ZnO films were determined by spectroscopic elipsometry measurements. Keywords: ZnO:Ga films, Transmittance, Ultrasonic spray pyrolysis technical , X-ray diffrachion, optical properties, electrical properties.