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Wide bandgap oxide semiconductors have gained significant attention in the fields from flat panel displays to solar cells, but their uses have been limited by the lack of high mobility p-type oxide semiconductors. Recently, β-phase TeO2 has been identified as a promising p-type oxide semiconductor with exceptional device performance. In this Letter, we report on the electronic structure of β-TeO2 studied by a combination of high-resolution x-ray spectroscopy and hybrid density functional theory calculations. The bulk bandgap of β-TeO2 is determined to be 3.7 eV. Direct comparisons between experimental and computational results demonstrate that the top of a valence band (VB) of β-TeO2 is composed of the hybridized Te 5s, Te 5p, and O 2p states, whereas a conduction band (CB) is dominated by unoccupied Te 5p states. The hybridization between spatially dispersive Te 5s2 states and O 2p orbitals helps us to alleviate the strong localization in the VB, leading to small hole effective mass and high hole mobility in β-TeO2. The Te 5p states provide stabilizing effect to the hybridized Te 5s-O 2p states, which is enabled by structural distortions of a β-TeO2 lattice. The multiple advantages of large bandgap, high hole mobility, two-dimensional structure, and excellent stability make β-TeO2 a highly competitive material for next-generation opto-electronic devices.

Severe Fermi level pinning at the interface of metal/n-Ge leads to the formation of a Schottky barrier. Therefore, a high contact resistance is introduced, debasing the performance of Ge devices. In this study, a Ge surface was treated by nitrogen plasma to form an ultra-thin Germanium oxynitride (GeO x N y ) passivation layer. It was found that the Schottky barrier height (SBH) of metal/n-Ge contact was strongly modulated by the GeO x N y interlayer, indicating alleviation of Fermi-level pinning effect. By adjusting the principal parameters of N 2 plasma treatment and additional post anneal, a Quasi-ohmic Al/n-Ge contact was achieved. Furthermore, the introduced GeO x N y layer gave extremely lower leakage current density of the gate stack for HfO 2 /Ge devices. These results demonstrate that GeO x N y formed by N 2 plasma would be greatly beneficial to the fabrication of the Ge-based devices.

High (1 1 1) orientation poly-Ge film was fabricated by Al induced crystallization (AIC), where Al and amorphous Ge (a-Ge) layers were continuously deposited by magnetron sputtering, avoiding the deliberate introduction of an AlOx interlayer. To improve the quality of poly-Ge film, the ratio of thicknesses of Al and a-Ge was adjusted. Electron backscattered diffraction (EBSD) results revealed that the (1 1 1) fraction of poly-Ge film reached 97% and the average crystal grain size surpassed 100 μm.

Here, we show a facile and versatile method-prepare highly ordered inorganic patterns on solid substrates by pyrolyzing UV cross-linked polymr/functional. precursor hybrid films. The crosslinked polymer matrix acted as structure-directing agent in a pyrolyzing process, whereas the functional precursor was converted into the skeleton of the micropatterns. The inorganic micropatterns could be further catalytically functionalized to grow CNT and ZnO nanorod arrays by simply changing different functional precursors. This simple technique offers new prospects in the field of micropatterns, nanolithography, and template.

NSFC [20433030, 20873108, 20423002]; NSF of Fujian Province [2007J0013]; Doctoral Program of Higher Education [20050384011]; Chinese Ministry of Education [106099]; [2009CB939804]

Plasma treatment and 10% NH 4 OH solution rinsing were performed on a germanium (Ge) surface. It was found that the Ge surface hydrophilicity after O 2 and Ar plasma exposure was stronger than that of samples subjected to N 2 plasma exposure. This is because the thin GeO x film formed on Ge by O 2 or Ar plasma is more hydrophilic than GeO x N y formed by N 2 plasma treatment. A flat (RMS 2 plasma treatment, showing its promising application in Ge low-temperature direct wafer bonding.

The amorphous Ti–Si mixed oxides prepared from chloride precursors using a one-step nonhydrolytic sol–gel route could serve as efficient gold catalyst supports for gas-phase epoxidation of propylen...