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Disorder‐induced Raman scattering effects in one‐dimensional ZnO nanostructures by incorporation and anisotropic distribution of Dy and Li codopants
Author(s) -
Cheng Baochang,
Sun Wei,
Jiao Jin,
Tian Baixiang,
Xiao Yanhe,
Lei Shuijin
Publication year - 2010
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.2590
Subject(s) - raman scattering , phonon , condensed matter physics , scattering , raman spectroscopy , materials science , molecular physics , anisotropy , surface phonon , chemistry , optics , physics
In Dy 3+ and Li + codoped ZnO nanowires, the additives accumulate preferentially in {0001} planes, resulting in serious breakdown of the translational symmetry in ab plane and modification of the phonon oscillation field. Not only acoustic overtones, silent optical modes, surface optical (SO) phonon modes, and multi‐phonon processes can be effectively observed in the nonresonant Raman scattering (RS) and the Fourier‐transform infrared (FTIR) spectra, but the quasi‐LO and TO modes of mixed A 1 and E 1 symmetry also show a noticeable red shift from E 1 symmetry (in ab plane) to A 1 symmetry (along c axis). The presence of dislocations and internal strain at the surface layer rich in additives, coming from the segregation of additives, forms a quasi‐bilayer system, resulting in the appearance and enhancement of SO phonon modes in RS and FTIR spectra. The Fano interference, originating from the interaction between the discrete scattering from phonons and the continuum scattering from laser‐induced electrons in the doped nanostructures, leads to typical asymmetric lineshapes on the lower wavenumber sides. Copyright © 2010 John Wiley & Sons, Ltd.