Optical phonon confinement in zinc oxide nanoparticles

Effect of confinement is investigated on optical phonons of different symmetries in the nanoparticles of zinc oxide with wurtzite structure using Raman spectroscopy. An optical phonon confinement model is used for calculating the theoretical line shapes, which exhibit different asymmetric broadening and shifts, depending on the symmetries of phonon and their dispersion curves. The best fit to the data is found for particle diameters consistent with those estimated using x-ray diffraction.

[1]  Horst Weller,et al.  Photochemistry of semiconductor colloids. Preparation of extremely small ZnO particles, fluorescence phenomena and size quantization effects☆ , 1985 .

[2]  A. Alivisatos.  Semiconductor Clusters, Nanocrystals, and Quantum Dots , 1996, Science.

[3]  Detlef W. Bahnemann,et al.  Preparation and characterization of quantum size zinc oxide: a detailed spectroscopic study , 1987 .

[4]  Howard W. H. Lee,et al.  ZnO nanoparticles embedded in polymeric matrices , 1996 .

[5]  W. Blau,et al.  Linear and nonlinear optical properties of semiconductor particles , 1990 .

[6]  A. Arora,et al.  Optical properties of selenium nanoparticles dispersed in polymer , 1999 .

[7]  W. Y. Liang,et al.  Transmission Spectra of ZnO Single Crystals , 1968 .

[8]  Philippe M. Fauchet,et al.  The effects of microcrystal size and shape on the one phonon Raman spectra of crystalline semiconductors , 1986 .

[9]  Michael Wraback,et al.  Structural, optical, and surface acoustic wave properties of epitaxial ZnO films grown on (0112) sapphire by metalorganic chemical vapor deposition , 1999 .

[10]  K. E. Remitz,et al.  Semiconductor doped glass as a nonlinear material , 1991 .

[11]  Denis L. Rousseau,et al.  First-Order Raman Effect in Wurtzite-Type Crystals , 1969 .

[12]  S. Risbud,et al.  Spectroscopic and structural characterization of electrochemically grown ZnO quantum dots , 1999 .

[13]  Louis E. Brus,et al.  Electron-electron and electron-hole interactions in small semiconductor crystallites : The size dependence of the lowest excited electronic state , 1984 .

[14]  S. K. Shumilov,et al.  Resonance Raman spectroscopy of electron-hole pairs - polar phonon coupling in semiconductor quantum microcrystals , 1991 .

[15]  C. Ironside,et al.  Three-dimensional phonon confinement in CdSe microcrystallites in glass , 1995 .

[16]  Takeda,et al.  Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials. , 1992, Physical review. B, Condensed matter.

[17]  Marc A. Anderson,et al.  Semiconductor clusters in the sol-gel process: quantized aggregation, gelation, and crystal growth in concentrated zinc oxide colloids , 1991 .

[18]  Cardona,et al.  Resonance Raman scattering by LO phonons in CdxHg1-xTe at the E0+ Delta 0 gap. , 1985, Physical review. B, Condensed matter.

[19]  A. Arora,et al.  The effect of annealing on the properties of nanoparticles dispersed in oxide glass containing Zn , 1997 .

[20]  L. Ley,et al.  The one phonon Raman spectrum in microcrystalline silicon , 1981 .

[21]  Gregory J. Exarhos,et al.  Influence of processing variables on the structure and properties of ZnO films , 1995 .

[22]  H. Bilz,et al.  Phonon Dispersion Relations in Insulators , 1979 .

[23]  A. Arora,et al.  Vibrational spectra of selenium nanoparticles dispersed in a polymer , 1999 .

[24]  Manuel Cardona,et al.  Resonant Raman scattering in ZnO , 1977 .

[25]  Arai,et al.  Low-frequency Raman scattering from CdS microcrystals embedded in a germanium dioxide glass matrix. , 1993, Physical review. B, Condensed matter.

[26]  P. Kamat,et al.  Photophysics and photochemistry of quantized ZnO colloids , 1992 .