Raman Scattering and Efficient UV Photoluminescence from Well-Aligned ZnO Nanowires Epitaxially Grown on GaN Buffer Layer

Cheng, Hsin‐Ming; Hsu, Hsu Cheng; Tseng, Yung-Kuan; Lin, Li-Jiaun; Hsieh, Wen‐Yuan

doi:10.1021/jp0442908

Cited by 110 publications

(70 citation statements)

References 45 publications

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“…Multiphonon scattering processes were previously reported for single crystalline bulk ZnO, 19 and recently for ZnO films, 20 ZnO nanowires, 21,22 and ZnO nanorods. 23,24 Although several RRS studies have been devoted to analyze the structure property of ZNAs, very few efforts have been made to address RRS in the postannealing effects on the ZNAs grown by low temperature chemical method, particularly to correlate with the change in defects.…”

Section: Introductionmentioning

confidence: 71%

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Annealing effects on optical properties of low temperature grown ZnO nanorod arrays

Yang

Zhao

Willander

et al. 2009

Journal of Applied Physics

128

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Vertically well-aligned ZnO nanorods on Si substrates were prepared by a two-step chemical bath deposition method. The structure and optical properties of the grown ZnO nanorods were investigated by Raman and photoluminescence spectroscopy. The results showed that after an annealing treatment at around 500°C in air atmosphere, the crystal structure and optical properties became much better due to the decrease in surface defects. The resonant Raman measurements excited by 351.1 nm not only revealed that the surface defects play a significant role in the as-grown sample, which was supported by low temperature time-resolved photoluminescence measurements, but also suggested that the strong intensity increase in some Raman scatterings was due to both outgoing resonant Raman scattering effect and deep level defect scattering contribution for ZnO nanorods annealed from 500 to 700°C.

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Section: Introductionmentioning

confidence: 71%

“…This is referred to as incoming and outgoing resonances, respectively. 46 Multiphonon scattering processes were previously reported for single crystalline bulk ZnO, 19 and recently for ZnO films, 20 ZnO nanowires, 21,22 and ZnO nanorods. 23,24 In all these cases the samples were excited by the 325 nm line of a He-Cd laser.…”

Section: -mentioning

confidence: 81%

Annealing effects on optical properties of low temperature grown ZnO nanorod arrays

Yang

Zhao

Willander

et al. 2009

Journal of Applied Physics

128

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“…34 The 437 cm À1 peak disappears in ZnO/Ag nanostructure due to overlapping with other stronger resonant Raman scattering peaks. It can be clearly seen that the peaks intensity of ZnO/Ag nanostructure is higher than that observed for ZnO nanostructure.…”

Section: Resultsmentioning

confidence: 99%

Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

et al. 2014

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We report on the synthesis of ZnO nanoplates and ZnO nanoplate/Ag nanoparticle heterostructures via a simple and cost effective wet chemical precipitation method. The prepared samples were characterized for structural and optical properties by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV-VIS reflectance, Raman, and FT-IR spectroscopy. The Kramers Kronig (K K) method and classical dispersion theory was applied to calculate the far-infrared optical constants such as, refractive index n(u), dielectric constant 3(u), transverse optical phonon (TO) and longitudinal (LO) optical phonon modes. We determined various optical constant values n(u) and 3(u) for ZnO nanostructures in the range of 0 to 9 and 0 to 70, respectively. Whereas, for Ag deposition on ZnO nanostructures, the corresponding n(u) and 3(u) values were found to be increased in the range of 0 to 30 and 0 to 800, respectively. The TO and LO optical phonon modes of ZnO nanoplate/Ag nanoparticle heterostructures were also found to be higher (416 cm 1 , 620 cm

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“…8,9 Specially, phonon dynamics of band gap engineered alloyed ZnO nanostructures such as Zn 1−x Mg x O and Zn 1−x Cd x O is a rarely studied area and requires further study. [10][11][12] Lattice vibrational properties of ZnMgO films grown by vapor phase methods have been investigated.…”

Section: Introductionmentioning

confidence: 99%

Phonon dynamics of Zn(Mg,Cd)O alloy nanostructures and their phase segregation

Ghosh¹,

Dilawar²,

Bandyopadhyay³

et al. 2009

Journal of Applied Physics

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Effective medium formulation for phonon transport analysis of nanograined polycrystals J. Appl. Phys. 111, 014307 (2012) Negative refraction of elastic waves in 2D phononic crystals: Contribution of resonant transmissions to the construction of the image of a point source AIP Advances 1, 041405 (2011) Thermal energy transport model for macro-to-nanograin polycrystalline semiconductors J. Appl. Phys. 110, 114310 (2011) Nanostructure model of thermal conductivity for high thermoelectric performance J. Appl. Phys. 110, 114306 (2011) Additional information on J. Appl. Phys. In this paper we report phonon dynamics in chemically synthesized Zn 1−x Mg x O ͑0 Յ x Յ 0.07͒ and Zn 1−y Cd y O ͑0 Յ y Յ 0.03͒ alloy nanostructures of sizes ϳ10 nm using nonresonant Raman and Fourier transformed infrared spectroscopy. Substitution by Mg makes the unit cell compact while Cd substitution leads to unit cell expansion. On alloying, both A 1 ͑LO͒ and E 1 ͑LO͒ mode of wurtzite ZnO show blueshift for Zn 1−x Mg x O and redshift for Zn 1−y Cd y O alloy nanostructures due to mass defect and volume change induced by the impurity atoms. Significant shift has been observed in E 1 ͑LO͒ mode for Zn 1−x Mg x O ͑73 cm −1 for x = 0.07͒ and Zn 1−y Cd y O ͑17 cm −1 for y = 0.03͒ nanostructures. The variation in Zn͑Mg,Cd͒-O bond length determined from the blue-͑red-͒ shift of IR bands on alloying with Mg ͑Cd͒ is consistent with their respective ionic sizes and the structural changes predicted by x-ray diffraction study. However, on progressive alloying one can detect phase segregation ͑due to presence of interstitial Mg and Cd ions͒ in the alloy nanostructures for relatively higher Mg and Cd concentrations. This is confirmed by the gradual absence of the characteristic IR and Raman bands of wurtzite ZnO near 400-600 cm −1 as well as by x-ray and TEM studies.

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Raman Scattering and Efficient UV Photoluminescence from Well-Aligned ZnO Nanowires Epitaxially Grown on GaN Buffer Layer

Cited by 110 publications

References 45 publications

Annealing effects on optical properties of low temperature grown ZnO nanorod arrays

Annealing effects on optical properties of low temperature grown ZnO nanorod arrays

Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

Phonon dynamics of Zn(Mg,Cd)O alloy nanostructures and their phase segregation

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