Tailored electric and optical properties of Nd doped ZnO: from transparent conducting oxide to photon down-shifting thin films

In this research, alternative deposition process of ZnO-based thin films have been studied for transparent conducting oxide (TCO) application. To improve the electrical and optical properties of transparent oxide thin films, alternatively stacked Al-doped ZnO and In-doped ZnO thin films were investigated. Multilayer structure of alternative 6 layers of thin films were prepared in this research. Especially, Aluminum and Indium were chosen as dopant materials. Thin films of Al-doped ZnO (AZO) and In-doped ZnO (IZO) were alternatively deposited by spin coating with sol-gel method. After deposition of multilayered thin films, multi steps of furnace (F), rapid thermal annealing (R) and CO2 laser annealing (L) processes were carried out and investigated thin film properties by dependence of post-annealing sequence and thin film structures. The electrical and optical properties of thin films were investigated by 4-point probe and UV-vis spectroscopy and its shows the greatest sheet resistance value of 0.59 kΩ/sq. from AZO/IZO multilayered structure and upper 85% of transmittance. The structural property and surface morphology were measured by X-Ray Diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The Al- and In-doped ZnO thin film shows the highest intensity value at (002) peak of AZO/IZO multilayer structure which was performed FRL process.

Download Full-text

Preparation and Characterization of Transparent Conducting Mn and Ni-Doped Zinc Oxide Films Prepared by Successive Ionic Layer Adsorption and Reaction Method

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2020.2750 ◽

2020 ◽

Vol 15 (1) ◽

pp. 101-107

Author(s):

M. Karunakaran ◽

L. Bruno Chandrasekar ◽

K. Kasirajan ◽

R. Chandramohan

Keyword(s):

Thin Films ◽

Transparent Conducting Oxide ◽

Hexagonal Structure ◽

Silar Method ◽

Texture Coefficients ◽

Transparent Conducting ◽

Doped Zno ◽

Diffraction Patterns ◽

Metal Doped

This paper reported the preparation and characterization of transparent conducting oxide thin films. Undoped and doped ZnO thin films were prepared by SILAR method. The micro-structural and optical properties were investigated. X-ray diffraction patterns revealed that the prepared thin films are polycrystalline in nature and has a hexagonal structure. The micro-structural properties of prepared thin films were calculated and crystallite size tends to changes due to dopant. The texture coefficients have been evaluated and found to be greater than unity revealing high texturing of the film. Undoped and Mn-doped ZnO prefer the orientation of (002) but Ni-doped ZnO and Mn and Ni co-doped ZnO prefers (100) orientation. The transmittance spectra of pure and transition metal-doped films were plotted against UV-Vis-NIR region and found that the transmittance changes with dopant and nature of doping. The optical band gap values were found to be in the range of 3.00–3.39 eV. The optical constants such as extinction coefficient, refractive index, dielectric constant and optical conductivity were examined.

Download Full-text