This paper presents a new way to study passivation mechanism of SiN<sub>x</sub>-Si interface using capacitance-voltage method. Fixed charge density (N<sub>f</sub>) near dielectric/Si interface, which is closely related to field effect passivation, and interface trap density (D<sub>it</sub>) at dielectric/Si interface, which is closely related to chemical passivation, can be obtained directly from experimental CV characteristics. The passivation properties of SiN<sub>x</sub>-Si can be studied and optimized by the MIS model.
Transparent <i>p</i>-type conductive CuGaO<sub>2</sub> films have been fabricated on sapphire substrates by sol–gel method. The stable sol solution for CuGaO<sub>2</sub> were formed by copper(II) acetate monohydrate and gallium(III) nitrate hydrate, and the <i>c</i>-axis orientation of CuGaO<sub>2</sub> films were strengthened with increasing annealing temperature. The pure phase CuGaO<sub>2</sub> film was obtained at 900°C for 30 min in N<sub>2</sub> atmosphere, and its microstructure, compositions, optical and electrical properties were analyzed. It was found that the sol-gel derived CuGaO<sub>2</sub> films show a high optical transparency (60-80%) in the visible region, the direct and indirect band gaps were approximately 3.56 and 3.24 eV, respectively. It shows a crossover from the thermal activation behavior to that of three-dimensional variable range hopping from the temperature-dependent electrical conductivity at about 160 K.