Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Physical metallurgy of Ti–Ni-based shape memory alloys

羟氨苄青霉素引起大疱性类天疱疮样疹

Physical Review B

Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

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Light-emitting diodes

Lasing is experimentally demonstrated in a direct bandgap GeSn alloy, grown directly onto Si(001). The authors observe a clear lasing threshold as well as linewidth narrowing at low temperatures.

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Lasing in direct-bandgap GeSn alloy grown on Si

The growth of microcrystalline silicon prepared by plasma-enhanced chemical vapour deposition depends on the deposition conditions and yields films with variable content of crystalline grains, amorphous network, grain boundaries and voids. The changes in the structural properties of a series of films grown under a variation of the dilution of the process gas silane in hydrogen, which induces a transition from highly crystalline to amorphous growth, were investigated. The evolution of the crystalline volume fraction was quantitatively analysed by Raman spectroscopy and X-ray diffraction. The results confirm the need for proper correction of the Raman data for optical absorption and Raman cross-section. Transmission electron microscopy was used to investigate the characteristics and the variation in the microstructure. Upon increasing the silane concentration the strong columnar growth with narrow grain boundaries degrades towards the growth of small irregularly shaped grains enclosed in an amorpho...

Structural properties of microcrystalline silicon in the transition from highly crystalline to amorphous growth

http://ematweb.cmi.ua.ac.be/emat/pdf/1574.pdf

Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy

The influence of the plasma excitation frequency on the growth conditions and the material properties of microcrystalline silicon prepared by plasma enhanced chemical vapor deposition at low deposition temperature is investigated. It is found that an increase of the plasma excitation frequency leads to a simultaneous increase of the growth rate, the grain size, and the Hall mobility of microcrystalline silicon. This is attributed to an effective selective etching of disordered material creating more space to develop crystalline grains, while also more species for faster growth of the crystallites are available.

/pdf/improvement-of-grain-size-and-deposition-rate-of-anhmbowfck.pdf

Improvement of grain size and deposition rate of microcrystalline silicon by use of very high frequency glow discharge

In this study a simple route to preparing photochromic silver nanoparticles in a TiO2 matrix is presented, which is based upon sputtering and subsequent annealing. The formation of silver nanoparticles with sizes of some tens of nanometers is confirmed by x-ray diffraction and transmission electron microscopy. The inhomogeneously broadened particle-plasmon resonance of the nanoparticle ensemble leads to a broad optical-absorption band, whose spectral profile can be tuned by varying the silver load and the annealing temperature. Multicolor photochromic behavior of this Ag–TiO2 system upon irradiation with laser light is demonstrated and discussed in terms of a particle-plasmon-assisted electron transfer from the silver nanoparticles to TiO2 and subsequent trapping by adsorbed molecular oxygen. The electron depletion in the nanoparticles reduces the light absorption at the wavelength of irradiation. A gradual recovery of the absorption band is observed after irradiation, which is explained with a slow therm...

Martina Luysberg

Papers

Lasing in direct-bandgap GeSn alloy grown on Si

Structural properties of microcrystalline silicon in the transition from highly crystalline to amorphous growth

Quantitative atomic resolution mapping using high-angle annular dark field scanning transmission electron microscopy

Improvement of grain size and deposition rate of microcrystalline silicon by use of very high frequency glow discharge

Photochromic silver nanoparticles fabricated by sputter deposition