The optoelectronic properties and role of Cu concentration on the structural and electrical properties of Cu doped ZnO nanoparticles

• Published in: Physica. B, Condensed matter Vol. 537; pp. 167 - 175
• Main Authors: Omri, K., Bettaibi, A., Khirouni, K., El Mir, L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-05-2018; Elsevier BV
• Subjects: Absorption spectra; Copper; CZO nanostructures; Doping; Doppler effect; Electric properties; Electrical properties; Electrical resistivity; Energy gap; Impedance spectroscopy; Nanoparticles; Nanostructured materials; Optical properties; Optoelectronic properties; Optoelectronics; Red shift; Sol-gel process; Sol-gel processes; Spectrum analysis; Wurtzite; Zinc oxide; Impedance spectroscopy; Optoelectronic properties; CZO nanostructures; Sol-gel process
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2018.02.025

In the current study, we synthesized a Cu-doped ZnO (CZO) nanoparticles material using a sol-gel method with different doping concentrations of Cu (0, 2, 3 and 4 at.%). The control of the Cu concentration on structural, electrical and optical properties of CZO nanoparticles was investigated in detail. The XRD analysis of the CZO nanoparticles reveals the formation of ZnO hexagonal wurtzite structure for all samples which confirm the incorporation of Cu2+ ions into the ZnO lattice by substitution. Furthermore, CZO nanoparticles showed a small red shift of absorption band with the incorporation of Cu from 0 to 4 at.%; i.e. a decreased band gap value from 3.34 eV to 3.27 eV with increasing of Cu doping content. The frequency dispersion of the electric conductivity were studied using the Jonscher universal power law, according to relation σ(ω) = σDC + A ωs(T). Alternative current conductivity increases with increasing Cu content in spite of the decrease the activation energy with copper loading. It was found that the conductivity reached its maximum value for critical Cu concentration of 3 at.%. The frequency relaxation phenomenon was also investigated and all results were discussed in term of the copper doping concentration.
•Cu-doped ZnO nanoparticles has been synthesized by sol-gel method.•The average diameter of undoped and Cu-doped ZnO nanoparticles was 33 nm and 43 nm.•Electric conductivity and electrical properties were investigated.•The Cu-doped ZnO nanoparticles shall be beneficial for optoelectronic applications.