Raman scattering studies of Mn-doped ZnO thin films deposited under pure Ar or Ar + N2 sputtering atmosphere

• Published in: Thin solid films 2010-12, Vol.519 (4), p.1272-1276
• Main Authors: HU, Y. M, WANG, C. Y, LEE, S. S, HAN, T. C, CHOU, W. Y
• Format: Article
• Language: English
• Subjects: Atmospheres; Cross-disciplinary physics: materials science; rheology; Defects; Deposition; Deposition by sputtering; Dopants; Exact sciences and technology; Manganese; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Sputtering; Thin films; Zinc oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.09.023

This paper investigates the anomalous and specific Raman modes present in Mn-doped ZnO thin films deposited using the magnetron co-sputtering method. To trace these peaks, we prepared Mn-doped ZnO films with different Mn concentrations by altering the sputtering power of the Mn target in a pure Ar or Ar+N2 sputtering atmosphere. A broad band observed in the Raman spectra of heavily Mn-doped ZnO films ranges from 500 to 590cma degree 1. This band involves the enhanced A 1 longitudinal mode and activated silent modes of ZnO, as well as a characteristic mode of Mn2O3. Four anomalous Raman peaks at approximately 276, 510, 645 and 585cma degree 1 are present in pure and Mn-doped ZnO films deposited under the Ar+N2 sputtering atmosphere. The peaks at 276cma degree 1 and 510cma degree 1 may originate from the complex defects of Zni-NO and Zni-Oi, respectively, while the peak at approximately 645cma degree 1 could be due to a complex defect of Zni coupled with both the N and Mn dopants. The results of this study suggest classifying the origins of anomalous and specific Raman peaks in Mn-doped ZnO films into three major types: structural disorder and morphological changes caused by the Mn dopant, Mn-related oxides and intrinsic host-lattice defects coupled with/without the N dopant.