Optimizing the structural, morphological and thermoelectric properties of zinc oxide by the modulation of cobalt doping concentration

A study is conducted to determine the effects of cobalt doping concentration on structural, morphological and thermoelectric properties of Zinc Oxide (ZnO). To test this hypothesis, cobalt doped zinc oxide nanoparticles are prepared by hydrothermal method by modulating the Cobalt (Co) concentration from 0.1 to 0.5. The X-Ray Diffraction (XRD) and Raman data is suggested that crystallinity of grown samples is found to be decreased by increasing the concentration of Co atoms. The poor crystallinity of the sample having higher concentration of Co atoms is due to the emergence of secondary phases. The value of Seebeck coefficient is also improved with doping as indicated by the high Seebeck value (250 mu V/degrees C) of Zn0.5Co0.5O. This enhancement of Seebeck coefficient is linked with the number of secondary phases. In contrast, electrical conductivity is reduced due to the generation of the impurity level close to the conduction band. In conclusion, at higher doping content, the overall power factor is enhanced with a slow increase in Seebeck coefficient and decrease in electrical conductivity by doping content. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study shows that increasing cobalt doping concentration decreases the crystallinity of the material, leading to the emergence of secondary phases. Although the Seebeck coefficient is improved, the electrical conductivity decreases. At higher doping content, the overall power factor is enhanced.