The effect of annealing on structural and optical properties of ZnO thin films grown by pulsed filtered cathodic vacuum arc deposition

Abstract

Thin ZnO films were deposited at room temperature on glass substrates by a pulsed filtered cathodic vacuum arc deposition system. The crystallographic structure and the size of the crystallites in the films were studied by means of x-ray diffraction. These measurements show that all the films are crystallized in the wurtzite form, present in a preferred orientation along the (002) direction, and the grain size is estimated to be 18.9-42 nm. The crystallite sizes were found to increase and the x-ray diffraction patterns were sharpened by annealing. Optical properties of the ZnO films were studied using a UV-visible spectrometer and calculations made using the envelope method. The absorption coefficient and optical band gap of the films were increased while the refractive index was decreased by annealing. The best annealing temperature for pulsed cathodic vacuum arc deposition grown ZnO thin films on glass substrates was found to be 600 • C from optical properties. This temperature is as high as can be measured for glass substrates samples because of the glass properties.

Influence of Thermal Process on Physical Properties of ZnO Films Prepared by Spray Pyrolysis

“…So, the improvement of the transmittance for annealed samples could be related to decrease in optical scattering processes after annealed. This kind of eect has been reported by Senadm et al [24], Ma et al [25] and Mahmood et al [26].…”

Dependence of film thickness on the structural and optical properties of ZnO thin films

“…The details of the PFCVAD system have been described elsewhere [10]. The cylindrical vacuum chamber was made of stainless steel (486 mm diameter and 385 mm in length) and evacuated using a primary and a turbomolecular pump (500 lt/s) to a base pressure below 1.3 Â 10 À8 Torr.…”

“…The films usually adhere well due to the induced ion mixing by the bombardment of energetic particles. Recently, polycrystalline ZnO semiconductor thin films produced by FCVAD have been reported [9,10].…”

Effects of post-thermal annealing on the optical constants of ZnO thin film

“…Optically pumped UV ZnO lasing has already been demonstrated at room temperature [1] and high temperatures [2]. A variety of methods have been employed to fabricate ZnO thin films, such as pulsed filtered cathodic vacuum arc deposition [3], RF magnetron sputtering [4], chemical vapor deposition [5], spray pyrolysis [6], and sol-gel process [7][8][9]. Despite the lower crystalline quality compared to those fabricated at vacuum deposition techniques, sol-gel technique still provides a method of preparing a small or large-area coating of ZnO thin film at low cost for technological applications.…”