The authors report on the optical properties of nanocrystalline ZnO grown at 200°C by radio-frequency magnetron sputtering. The nanocrystalline nature of the films was confirmed by cross-sectional transmission electron microscopy. In these films, ZnO nanocrystals with an average size of about 3–5nm were embedded in an amorphous matrix. The photoluminescence spectra from such nanostructured thin films show the near-band-edge emissions around 3.3eV. A redshift of about 8–11cm−1 is observed in the case of first-order longitudinal-optical (LO) phonon of ZnO in such nanostructures when compared to the LO phonon peak of bulk ZnO. The ultraviolet resonant Raman excitation at 77K shows multiphonon LO modes up to eighth order.

Articles you may be interested inThe effect of nanocrystallite size in monoclinic HfO 2 films on lattice expansion and near-edge optical absorption

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Wandering spleen is a rare occurrence. Torsion of the splenic pedicle is the major life-threatening complication of this entity. Preoperative diagnosis is based on radiological investigation. We report two consecutive cases, one adult and one child, in whom torsion in a wandering spleen was diagnosed based on a typical whirled appearance of the splenic vessels on computed tomography. We present a review of computed tomographic appearance of splenic torsion, and emphasize the "whirled appearance" as a specific sign for splenic torsion in wandering spleen.

Articles you may be interested inCoplanar amorphous-indium-gallium-zinc-oxide thin film transistor with He plasma treated heavily doped layer Appl. Phys. Lett.Highest transmittance and high-mobility amorphous indium gallium zinc oxide films on flexible substrate by roomtemperature deposition and post-deposition anneals Appl. Phys. Lett. 99, 051901 (2011); 10.1063/1.3619196 Role of order and disorder on the electronic performances of oxide semiconductor thin film transistorsWe investigated the amorphous region of the In 2 O 3 -ZnO material system. The composition dependence of the amorphous region was explored and the films exhibited an n-type semiconductor behavior with low resistivities in the range of 4 ϫ 10 −4 -6.33ϫ 10 −4 ⍀cm. These amorphous films have a very wide transmittance window range of 300-2500 nm, and the transmittance is higher than 85% in the fiber-optics telecommunication window of 1.30-1.55 m. The band gap of amorphous films can be engineered from 2.66 to 3.05 eV, by varying the zinc/ ͑zinc+ indium͒ atomic ratio. A monotonous decrease in mobility from 71.6 to 59.4 cm 2 / V s was observed with an increase in zinc/ ͑zinc+ indium͒ atomic ratio from 0.19 to 0.43 in the amorphous region. This trend was explained on the basis of percolation theory and overlap integral calculations. The effective mass of these amorphous films was calculated using the Drude model in the free-carrier absorption region and correlated with composition as well as the carrier concentration of the films.