Effect of Annealing Temperature on Structural and Optical Properties of CdO Thin Films Prepared by pulsed laser deposited (PLD) technique

Jassim M Marie,Abdul-Majeed E Ibrahim,Kadhim A Adim

doi:10.32894/kujss.2018.13.1.2

Abstract

In this paper Cadmium oxide (CdO) thin films has attracted interest due to its potential applications in optoelectronics devices. thin films were grown on glass substrates by the pulsed laser deposition (PLD) technique at room temperature and different annealing temperatures Ta=(573,673 and 773) K. The structural studies (XRD) measurements for CdO thin film is polycrystalline with cubic structure and it is evident that the film is highly oriented in the (111) direction. Atomic force microscopy (AFM) was used to examine CdO surfaces, After annealing the films become more homogeneity and notice to increment the root mean square, surface roughness and average grain size. The optical properties of CdO thin films are studied as a function to wavelength in region (375 - 1100) nm. The optical transmittance of the prepared CdO films notice that the transmittance pattern of all deposited thin films increases with increasing the annealing temperature (Ta). The direct energy gap for CdO films was decreases with increasing of annealing temperature for all samples due to the growth of the crystallites .The optical constants such as refractive index, extinction coefficient and dielectric constant were also calculated.

Highlights

Transparent conducting oxides (TCOs) are potential candidates for energy efficient devices like solar cells, light emitting diodes, photo detectors because of their high transparency in the visible region and high electrical conductivity at room temperature [1]
3.1 Structural properties The X-ray diffraction patterns of Cadmium oxide (CdO) thin films grown on glass substrate were prepared by pulsed laser deposition (PLD) at different annealing temperatures Ta=(573, 673 and 773 )K for 2 hour
All the films show polycrystalline nature containing cubic structure of pure CdO phase are shown in Fig. (4)

Summary

Introduction

Transparent conducting oxides (TCOs) are potential candidates for energy efficient devices like solar cells, light emitting diodes, photo detectors because of their high transparency in the visible region and high electrical conductivity at room temperature [1]. CdO films have been successfully used for many applications, including phototransistors [7], gas sensor [8], transparent electrodes, photovoltaic solar cells [9], liquid crystal displays, photodiodes, IR detectors and anti-reflection coatings and optoelectronic devices [1,9] It is a promising candidate for a transparent conducting oxide material because it has a simple rock-salt crystal structure, high carrier mobility, and high conductivity [10]. Many investigators were done this modification of the deposition technique from time to time with the aim of obtaining better quality films by this process These include rotation of the target, a positioning of the substrate with respect to the target. Angstrom Ad-Vance Inc, tip NSC35/AIBS). the optical measurements of thin films depend on, thickness, homogeneity, structure, materials used and the preparation conditions. were measured using UV/ Visible SP-8001 spectrophotometerover the range ( 375-1100) nm

Results and discussion

Optical Properties

The Optical Energy Gap

Conclusions