This paper presents a new way to study passivation mechanism of SiNx-Si interface using capacitance-voltage method. Fixed charge density (Nf) near dielectric/Si interface, which is closely related to field effect passivation, and interface trap density (Dit) at dielectric/Si interface, which is closely related to chemical passivation, can be obtained directly from experimental CV characteristics. The passivation properties of SiNx-Si can be studied and optimized by the MIS model.
Transparent p-type conductive CuGaO2 films have been fabricated on sapphire substrates by sol–gel method. The stable sol solution for CuGaO2 were formed by copper(II) acetate monohydrate and gallium(III) nitrate hydrate, and the c-axis orientation of CuGaO2 films were strengthened with increasing annealing temperature. The pure phase CuGaO2 film was obtained at 900°C for 30 min in N2 atmosphere, and its microstructure, compositions, optical and electrical properties were analyzed. It was found that the sol-gel derived CuGaO2 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.