Suyuan Wang

Preparation and photoluminescence of highly ordered TiO2 nanowire arrays

Highly ordered TiO2 nanowire (TN) arrays were prepared in anodic alumina membranes (AAMs) by a sol-gel method. The TNs are single crystalline anatase phase with uniform diameters around 60 nm. At room temperature, photoluminescence (PL) measurements of the TN arrays show a visible broadband with three peaks, which are located at about 425, 465, and 525 nm that are attributed to self-trapped excitons, F, and F+ centers, respectively. A model is also presented to explain the PL intensity drop-down of the TN arrays embedded in AAMs: the blue PL band of AAMs arises from the F+ centers on the pore walls, and the TNs first form in the center area of the pores and then extend to the pore walls.

Influence of Sb doping on the structural and optical properties of tin oxide nanocrystals

The influence of Sb doping on the structural and optical properties of the SnO2 nanocrystals and films were investigated. An unusual enhancement in near infrared absorption was found in the SnO2 nanocrystals with increasing Sb doping content, and the maximum absorption shifted to shorter wavelength.

Surface localized exciton emission from undoped SnO2 nanocrystal films

We report the UV photoluminescence properties of SnO2 nanocrystalline films. A free exciton decay centered at 3.7 eV and a strong surface localized exciton emission peak at 3.3 eV have been observed at room temperature. The peak energy of the surface localized exciton emission exhibits a redshift with increasing temperature and a blueshift with increasing excitation intensity. The surface localized exciton emission is considered to originate from the radiative recombination of exciton within the surface region of SnO2 nanocrystals. The surface defects and local disorder are believed to be responsible for the formation of band tail states at the conduction band and potential well within the band tails.

Single-crystalline Ge1-x-ySixSny alloys on Si (100) grown by magnetron sputtering

Magnetron sputtering was successfully used to grow single-crystalline Ge1-x-ySixSny ternary alloys on Si (100) substrates. The lattice constants of the alloys were calculated by X-ray diffraction and corrected Vegard’s law, respectively, showing that the corrected Vegard’s law is suitable for the Ge1-x-ySixSny lattice constants. Thermal stability investigations showed that the Ge0.85Si0.051Sn0.099 alloy was stable at 500 °C. The Ge1-x-ySixSny can maintain good crystalline quality under moderate annealing temperature, with no indication of phase segregation or Sn precipitation. Optical absorption measurements were carried out at room temperature to determine the band gap energies of the Ge1-x-ySixSny alloys. These results suggest that magnetron sputtering is an effective alternative method to grow Ge1-x-ySixSny alloys for fabrication of novel devices.

Ni(Ge 1− x − y Si x Sn y ) Ohmic Contact Formation on p-type Ge 0.86 Si 0.07 Sn 0.07

A single-crystalline Ge0.86Si0.07Sn0.07 alloy was grown on double Ge1− x Sn x and Ge buffers on Si (100) using magnetron sputtering. The temperature-dependent contact resistivity (

Ni(Ge1−x−ySixSny) Ohmic Contact Formation on p-type Ge0.86Si0.07Sn0.07

\rho _{\mathrm {c}})

P+-Ge1−xSnx / p−-Ge1−x−ySixSny / n-Ge1−x−ySixSny NTFET analysis and the realization of n-Ge1−x−ySixSny ohmic contact

of Ni/p-type Ge0.86Si0.07Sn0.07 structure was investigated in detail. Good ohmic contacts with

Ni ohmic contacts to n-type Ge1−x−ySixSny using phosphorous implant and segregation

\rho _{\mathrm {c}}

Fe3O4@SiO2 Core/Shell Nanoparticles: The Silica Coating Regulations with a Single Core for Different Core Sizes and Shell Thicknesses

of

Ag-decorated TiO2 nanograss for 3D SERS-active substrate with visible light self-cleaning and reactivation

\sim 1.96 \times 10^{\mathrm {-6}}\Omega \cdot {\rm cm}^{\mathrm {-2}}