Influence of isovalent Cd doping concentration and temperature on electric and dielectric properties of ZnO films
| Autor: | Büşra Altun, Selim Acar, Ahmad Ajjaq, Ali Orkun Çağırtekin, Irmak Karaduman Er, Fatma Sarf |
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| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science Process Chemistry and Technology Doping Analytical chemistry 02 engineering and technology Dielectric Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials 0103 physical sciences Materials Chemistry Ceramics and Composites Nanorod Grain boundary Crystallite 0210 nano-technology Chemical bath deposition Wurtzite crystal structure |
| Zdroj: | Ceramics International. 47:27251-27266 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2021.06.147 |
| Popis: | In this study, pure zinc oxide and lightly cadmium doped zinc oxide (Zn1-xCdxO; x = 0.01, 0.03, 0.05 and 0.07) films were synthesized by chemical bath deposition to mainly investigate the possible impact of isovalent (in particular Cd) doping ratio and temperature on their electric and dielectric features. X-ray diffraction patterns revealed that all produced films have a dominance of ZnO hexagonal wurtzite structure with the emergence of a minor CdO cubic phase at x ≥ 0.03, and predicted the decrease in average crystallite sizes with Cd doping. Cd content in the films was verified by energy dispersive X-ray analysis. Images of scanning electron microscopy revealed the formation of nanorods and spheres on the surface of pure ZnO film which changed to porous/agglomerative spheres with Cd doping. Then a comprehensive electric and dielectric analysis was carried out as a function of frequency in a wide temperature range (300–700 K) using two separate experimental data sets, (Z, θ) and (C, G). The results demonstrated the critical effect of temperature and Cd doping ratio on the electrical and dielectric properties of ZnO films. Among the investigated films, Zn0·97Cd0·03O film recorded highest conductivity and enhanced dielectric properties which was attributed to the equal activation of grains and grain boundaries in the film structure verified by the estimation of activation energies from impedance spectrum. However, the effect of Cd doping on electric and dielectric properties was prominent only below 500 K, beyond which the doping effect became negligible which might be correlated with the effective dominance of grain boundaries at high temperatures as was witnessed by modulus spectrum. |
| Databáze: | OpenAIRE |
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