In this study, the authors deposited silicon oxynitride films by Radio Frequency Plasma Enhanced Chemical Vapour Deposition (RF PECVD) method. The research explores the relationship between the deposition process parameters and the optical properties of the deposited SiO x N y films. The optical constants of SiO x N y films were measured and calculated by spectroscopic ellipsometry method. Additionally, the authors investigated the possibility of controlling the deposited film composition by the flow ratio of different gaseous precursors: ammonia (NH 3 ), diluted silane (2%SiH 4 /98%N 2 ), nitrous oxide (N 2 O) and nitrogen (N 2 ). The gas mixture introduced to the working chamber during the growth of the film has the influence on the Si-O and Si-N bonds formation and the ratio between these bonds determines the refractive index of the deposited film.
In this work, the photocatalytic properties of thin films based on titanium oxides for application on flexible glass in photovoltaic panels were presented. Thin films were prepared by gas impulse magnetron sputtering (GIMS), where the gas injection on a target was synchronized in time with the electric pulse supplying the magnetron with the Ti target. The deposition process was carried out under various Ar/O2 atmospheres (with a content of 5–8% O2). The as-deposited TiOx films were non-stoichiometric. The influence of deposition parameters on optical properties, microstructure, hardness, and elastic modulus was examined. In addition, the dependence between the oxygen content in the sputtering atmosphere and the photocatalytic activity of the coatings was examined. The scratch resistance of the coatings and their adhesion to flexible glass were also investigated. It has been shown that the GIMS technique can be used for efficient deposition of non-stoichiometric TiOx coatings on substrates sensitive to the temperature as thin flexible glass and, at the same time, characterized by high adhesion. The TiOx-based semiconductor coatings prepared in this study can be used successfully in transparent electronics and in the construction of modern photovoltaic panels due to their photocatalytic activity, high hardness, and high level of transparency.
Basic knowledge about the factors and mechanisms affecting the performance of solar cells and their identification is essential when thinking of future improvements to the device. Within this paper, we investigated the current transport mechanism in GaAsN p-i-n solar cells grown with atmospheric pressure metal organic vapour phase epitaxy (AP-MOVPE). We examined the electro-optical and structural properties of a GaAsN solar cell epitaxial structure and correlated the results with temperature-dependent current-voltage measurements and deep level transient spectroscopy findings. The analysis of J-V-T measurements carried out in a wide temperature range allows for the determination of the dominant current transport mechanism in a GaAsN-based solar cell device and assign it a nitrogen interstitial defect, the presence of which was confirmed by DLTFS investigation.
In this work, selected properties of metallic and oxide thin films based on titanium and cobalt were described. Thin-film coatings were prepared using the magnetron sputtering method. The deposition was carried out from sintered targets with different Co-content (2 at.%, 12 at.% and 50 at.%). The relation between the Ti–Co target composition and the Co-content in the metallic and oxide films was examined. There was 15–20% more cobalt in the films than in the target. Moreover, the deposition rate under neutral conditions (in Ar plasma) was even 10-times higher compared to oxidizing Ar:O2 (70:30) plasma. A comprehensive analysis of the structural properties (performed with GIXRD and SEM) revealed the amorphous nature of (Ti,Co)Ox coatings, regardless of the cobalt content in the coating. The fine-grained, homogenous microstructure was observed, where cracks and voids were identified only for films with high Co-content. Optical studies have shown that these films were well transparent (60% ÷ 80%), and the amount of cobalt in the target from which they were sputtered had a significant impact on the decrease in the transparency level, the slight shift of the absorption edge position (from 279 nm to 289 nm) as well as the decrease in their optical band gap energy (from 3.13 eV to 1.71 eV). Electrical studies have shown that in (Ti,Co)Ox thin films, a unipolar memristive-like effect can be observed. The occurrence of such effects has not been reported so far in the case of TiO2 coatings with the addition of Co.
TiOx films were prepared by gas impulse magnetron sputtering under oxygen-deficient (ODC) and oxygen-rich conditions (ORC) and annealing at 100–800 °C was used. The O2 content had an effect on their transparency level (Tλ). The films from the ORC mode had ca. Tλ = 60%, which decreased slightly in the VIS range after annealing. The film from the ODC mode had lower transmission (ca. <10%), which increased in the NIR range after annealing by up to ca. 60%. Differences in optical band gap (Egopt) and Urbach energy (Eu) were also observed. The deposition parameters had an influence on the microstructure of TiOx coatings. The ORC and ODC modes resulted in columnar and grainy structures, respectively. Directly after deposition, both coatings were amorphous according to the GIXRD results. In the case of TiOxORC films, this state was retained even after annealing, while for TiOxODC, the crystalline forms of Ti and TiO2-anatase were revealed with increasing temperature. Sensor studies have shown that the response to H2 in the coating deposited under oxygen-rich conditions was characteristic of n-type conductivity, while oxygen-deficient conditions led to a p-type response. The highest sensor responses were achieved for TiOxODC annealed at 300 °C and 400 °C.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.