Experimental and theoretical studies of KxZn1-xO. Issue 1 (January 2020)

• Record Type: Journal Article
• Authors: Ma, Zhanhong; Ren, Fengzhang; Deng, Yafeng; Volinsky, Alex A.
• Is Part Of: Ceramics international. Volume 46:Issue 1(2020)
• Page Start: 763
• Page End: 767
• Publication Date: 2020-01
• Subjects: Zinc oxide -- K-doped -- Sol-gel method -- Electronic structure -- Optical performance; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.09.030
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this paper, K-doped ZnO nanocrystalline powders were prepared by the sol-gel method at 500 °C. The effects of potassium (K) doping on the particle size, phase composition, and light absorption properties of zinc oxide nanocrystals were investigated by X-ray diffraction, transmission electron microscopy and ultraviolet–visible spectroscopy. The main crystalline phase of the powders before and after K doping is wurtzite ZnO. With the increased K doping amount, the purple and blue luminescent peaks are enhanced. The band gap of the sample obtained from the light absorption spectra initially increased with the K doping amount, then decreased, and increased again with the K doping amount, which is consistent with the theoretical calculation results. The calculated energy band and density of states results show that when the K doping amount is small, the band gap is reduced because the K doping forms the impurity level and the conduction band moves downward. This decrease is due to the two impurity levels generated at the bottom of the valence band.