Raman study of doped-ZnO thin films

• Author(s): Cerqueira, M. F. ; Rolo, Anabela G. ; Viseu, T. M. R. ; Campos, J. Ayres de ; Arôso, T. de Lacerda ; Oliveira, F. ; Vasilevskiy, Mikhail ; Alves, E.
• Date: 2010
• Persistent ID: http://hdl.handle.net/1822/13721
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): ZnO; Doping; Raman scattering; Phonons
• Document Type: Article
• Language: English

Description

A Raman spectroscopy study of doped versus undoped ZnO layers is presented. The layers were grown by RF magnetron sputtering and the doping with Al, Sb and Mn was achieved by ion implantation with subsequent annealing. First-order Raman response measured under λ=488 nm excitation is discussed. It is shown that doping with any of the impurities used in this work produces a strong enhancement of the longitudinal optical (LO) phonon band, which is attributed to the intra-band Fröhlich mechanism. In addition, doping with Mn results in an extra mode located at 530 cm-1, tentatively attributed to a local vibrational mode of Mn substituting Zn in the lattice sites.