Narrow Results

The temperature and concentration dependences of the transmission spectrum of an aqueous solution of agar are investigated. Measurements taken in the heating and cooling modes show strong thermal hysteresis in the spectral properties. Analysis of the results suggests that the formation of a gel network occurs in a much narrower temperature range than its collapse. The study of the temperature dependence of transmittance indicates that the association bispirals by cooling the solution and responsible for the formation of network occurs at temperature about $40^{\circ }$C. A breakdown of these associates by heating of the gel begins at $60^{\circ }$C and covers a wide temperature range. The gel point $T_g$ and the gel melting point $T_m$ increase with increasing polymer concentration, but for $T_m$ this dependence is stronger. Growth of turbidity (light scattering) of gel by increasing of agar concentration is due to the increasing of number and size of gel associates.

ZnO + 1.5 wt.% TiO₂ powder is calcined at $1100^{\circ }\mathrm{\text{C}}$ and sintered at $1350^{\circ }\mathrm{\text{C}}$ to prepare the Ti-doped ZnO ceramic target, and RF sputtering is used to deposit F and Ti co-doped ZnO (FTZO) films by introducing Ar + CF₄ mixing gas (CF₄ flow rate is 0.2%) into the deposition chamber. The deposition temperature is changed from room temperature to $200^{\circ }\mathrm{\text{C}}$, and the thicknesses of all deposited FTZO films are controlled at about 320 nm. After FTZO films are deposited, X-ray diffraction pattern is used to analyze their crystalline properties, field-effect scanning electron microscope is used to observe their surface morphologies and confirm their thicknesses. n&k analyzer is used to measure the transmittance spectra in the wavelength range of 300–1100 nm and we find that the absorption edge of FTZO films is shifted to lower wavelength as the deposition temperature increases. The optical energy band gap of FTZO films is calculated using the transmittance spectra and the electrical properties of FTZO films are measured using a Hall equipment. Finally, secondary-ion mass spectrometry is used to analyze the C, O, F, Si and Ti elements with different deposition temperatures for confirming the existence and distribution of ${\mathrm{\text{F}}}^{-}$ ions and non-existence of C element.

Compositions of $0.2{\mathrm{\text{In}}}_2{\mathrm{\text{O}}}_3+0.8{\mathrm{\text{Ga}}}_2{\mathrm{\text{O}}}_3$ and $0.4{\mathrm{\text{In}}}_2{\mathrm{\text{O}}}_3+0.6{\mathrm{\text{Ga}}}_2{\mathrm{\text{O}}}_3$ were mixed and sintered at 1250${}^{\circ }$C to fabricate ${\mathrm{\text{In}}}_{0.4}{\mathrm{\text{Ga}}}_{1.6}{\mathrm{\text{O}}}_3$ and ${\mathrm{\text{In}}}_{0.8}{\mathrm{\text{Ga}}}_{1.2}{\mathrm{\text{O}}}_3$ targets, and RF sputtering method was used to deposit ${\mathrm{\text{In}}}_{0.4}{\mathrm{\text{Ga}}}_{1.6}{\mathrm{\text{O}}}_3$ and ${\mathrm{\text{In}}}_{0.8}{\mathrm{\text{Ga}}}_{1.2}{\mathrm{\text{O}}}_3$ films by introducing pure Argon during the deposition process. After ${\mathrm{\text{In}}}_{0.4}{\mathrm{\text{Ga}}}_{1.6}{\mathrm{\text{O}}}_3$ and ${\mathrm{\text{In}}}_{0.8}{\mathrm{\text{Ga}}}_{1.2}{\mathrm{\text{O}}}_3$ films were deposited, we used the X-ray diffraction pattern to analyze their crystalline properties, the ultraviolet–visible-infrared spectrophotometry to measure their transmittance spectra in the wavelength range of 200–800 nm, an X-ray photoelectron spectroscopy to find their composition variation, and a Hall equipment to measure their electrical properties, including the carrier concentration, the mobility, and the resistivity. We found that the absorption edges of ${\mathrm{\text{In}}}_{2x}{\mathrm{\text{Ga}}}_{2-2x}{\mathrm{\text{O}}}_3$ films were shifted to higher wavelength as $x$ value increased from 0.2 to 0.4. We also found that the Hall parameters of ${\mathrm{\text{In}}}_{0.4}{\mathrm{\text{Ga}}}_{1.6}{\mathrm{\text{O}}}_3$ film could not be measured because of its high resistivity. Therefore, ${\mathrm{\text{In}}}_{0.8}{\mathrm{\text{Ga}}}_{1.2}{\mathrm{\text{O}}}_3$ film was used to fabricate thin-film transistor (TFT), and the electrical properties of the fabricated TFT were also well investigated.