Doped Zno Thin Film Optical Properties Of The Research

Zinc oxide is a kind of wide band gap semiconductor material. In room temperature, it’s band gap width to3.37eV, exciton binding energy is high, non-toxic, easily available raw materials, low cost, excellent optical and electrical properties. In a photoelectric device, transparent conductive film, a surface acoustic wave device has been widely applied. At present, the zinc oxide semiconductor materials research hot spot and the focal point lies in:(1) how to get excellent performance and repeatable growth of P type zinc oxide, and preparation of efficient zinc oxide based LED and LD;(2) zinc oxide structure characteristics and special performance research and application, such as doping metal after the performance change. This paper focuses on the second research directions for experiments and analysis.Different preparation technology and process parameter determines the structure and optical properties of thin films. The preparation method of zinc oxide has many, such as:sputtering, pulsed laser deposition, molecular beam epitaxy and atomic layer deposition. The laboratory is used in atomic layer deposition method, so the paper firstly studies the different growth temperature, atomic layer deposition process of zinc oxide thin film growth rate. By ellipsometry, the zinc oxide film for optical measurement, and calculation of optical constants of thin film, such as refractive index and extinction coefficient, so that the low temperature under the conditions of the optimum growth conditions of zinc oxide thin film.Second zinc oxide as band gap is wide, the stoichiometric zinc oxide, itself should not semiconductor insulator. Although through the film in self compensation from Zn as a donor to provide free electrons, but appropriate doping metal can make the optical and electrical properties of more good, especially for zinc oxide thin film energy band engineering, appropriate doping can change the forbidden band widths, let the zinc oxide film is applied more and more extensively. The aluminum doped zinc oxide and hafnium thin films were measured by ellipsometry, to study the effect of different elements and different concentration of dopants on the optical properties of the films effects, eventually with the doping concentration is increased, the refractive index of the sample is reduced, the band width is increased.