Effects of Zn-doping on structure and electrical properties of p-type conductive CuCr1−x Zn x O2 delafossite oxide

• Published in: Journal of materials science Vol. 51; no. 7; pp. 3592 - 3599
• Main Authors: Chuai, Ya-Hui, Wang, Xin, Shen, Hong-Zhi, Li, Ya-Dan, Zheng, Chuan-Tao, Wang, Yi-Ding
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-04-2016; Springer Nature B.V
• Subjects: Activation energy; Chromium; copper; Doping; electrical conductivity; Electrical properties; Electrical resistivity; electrodes; industry; Materials science; Morphology; Optoelectronics; Organic chemistry; Oxides; Photoelectrons; Polarons; Seebeck effect; Sol-gel processes; sol-gel processing; Spectrum analysis; Temperature dependence; X ray photoelectron spectroscopy; X-ray diffraction; Zinc
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-015-9679-4

Delafossite-type CuCr₁₋ₓ Zn ₓ O₂ (x = 0, 0.03, 0.05, 0.07, 0.1) conductive oxides were synthesized by sol–gel method, and the effects of Zn-doping on morphology, structure, and electrical properties of the CuCr₁₋ₓ Zn ₓ O₂ oxides were investigated. Based on X-ray diffraction (XRD) and Raman spectrum, the crystalline quality of the oxides is improved by the suitable substitution of Cr by Zn. The X-ray photoelectron spectroscopy (XPS) spectra reveal the chemical state of Zn is +2. The Hall and Seebeck coefficients of the pellet samples display a positive sign, indicating p-type conductive characteristics of the obtained oxides. The temperature-dependent resistivity of the oxides is proven to be consistent with small polaron hopping. For the three oxide samples with x = 0, 0.05, and 0.1, the activation energies for the polaron hopping between Zn²⁺ and Cr³⁺ sites are 54, 41.5, 32 meV, respectively, which is found to decrease with the increase of Zn content. The electrical conductivity can be remarkably improved by Zn-doping due to the small polaron hopping activation energy. These properties render this material promising as transparent electrode in optoelectronic industry.