Investigação das propriedades ópticas de ZnO e ZnO:Al

• Main Author: Trindade, Neilo Marcos [UNESP]
• Publication Date: 2015
• Format: Doctoral thesis
• Language: por
• Source: Repositório Institucional da UNESP
• Download full: http://hdl.handle.net/11449/135936; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/25-02-2016/000858000.pdf
• topic: Óxido de zinco; Propriedades oticas; Modelagem computacional; Magnetrons; Zinc oxide

This thesis presents a study of the optical properties of thin films of pure ZnO and ZnO doped with Al; and a study of the influence of argon gas pressure of argon gas pressure variation during synthesis of films on the optical and structural properties. The films were deposited on glass and silicon substrate by RF magnetron suputtering technique with a target Zn-Al alloy with a concentration of 2% by weight of aluminum. The XRD analysis of the film showed a preferential peak in the (002) - c axis, showing the formation of a wurtzite structure corresponding to the ZnO, and that there is an increase in crystalline size with. Al doping, in agreement with results AFM. Measurements showed the characteristic. Raman vibration mode ZnO around 575 cm-1 and the improvement of crystallinity of the material with the doping of Al, without impairment to the variation of argon pressure. The films exhibited optical transmittance above 70% in the visible spectrum range (400 to 700 nm) and correlated with the reflectance spectrum enabled to obtain data such as the optical band gap in the range 3.5 to 3.6 eV which are above the values obtained for the intrinsic ZnO (3.3 eV). The optical gap results were correlated data obtained through Computational Modeling. The photoluminescence measurements showed a large light emission range in the visible region and emission lines at 3.32 and 3.37 eV suggest that Al doping effect. The optical resuts correlated with the computational modeling reinforce the Burstein-Moss effect is dominant for that material