The channel conduction in 4H-SiC metal–oxide–semiconductor field effect transistors (MOSFETs) are highly impacted by charge trapping and scattering at the interface. Even though nitridation reduces the interface trap density, scattering still plays a crucial role in increasing the channel resistance in these transistors. In this work, the dominant scattering mechanisms are distinguished for inversion layer electrons and holes using temperature and body-bias-dependent Hall measurements on nitrided lateral 4H-SiC MOSFETs. The effect of the transverse electric field ($E_{eff}$) on carrier mobility is analyzed under strong inversion condition where surface roughness scattering becomes prevalent. Power law dependencies of the electron and hole Hall mobility for surface roughness scattering are determined to be $E_{eff}^{-1.8}$ and $E_{eff}^{-2.4}$, respectively, analogous to those of silicon MOSFETs. Moreover, for n-channel MOSFETs, the effect of phonon scattering is observed at zero body bias, whereas in p-channel MOSFETs, it is observed only under negative body biases. Along with the identification of regimes governed by different scattering mechanisms, these results highlight the importance of the selection of substrate doping and of $E_{eff}$ in controlling the value of channel mobility in 4H-SiC MOSFETs.

This study presents the influence of pH control agents and pH value on the physical properties of ZnO thin films obtained by chemical bath deposition. ZnO thin films were synthesized on glass substrates using precursor solutions of different pHs prepared from two bases: sodium hydroxide (NaOH) and ammonia (NH₃). The effect of pH values on the morphological, structural, and optical properties of ZnO thin films was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV–Visible spectroscopy. XRD results showed that all the synthesized ZnO thin films are polycrystalline and crystallize in a hexagonal wurtzite structure. The crystallite size, calculated using the Debye–Scherrer formula, varied from 10.50 nm to 11.69 nm for ZnO thin films obtained with NH₃ and from 20.79 nm to 27.76 nm for those obtained with NaOH. FTIR analysis confirmed the presence of functional groups. SEM images indicated that not only the base but also the pH affects the morphology of the films, giving rise to different granular shapes. Overall, the ZnO thin films obtained with NaOH looked more mesoporous compared to those obtained with NH₃. Optical characterization results showed that whatever the base used, the pH of the precursor solution affected the ZnO thin film transmittance. Films synthesized with NH₃ exhibited the best transmittance (80%) at pH 8.5, while the best transmittance (81%) of films synthesized with NaOH was obtained at pH 8 in the visible region. Based on optical and morphological properties, ZnO films obtained from NH₃ at pH 8.5 are found to be more suitable as photoanodes in dye-sensitized solar cells.

Using electrochemical impedance spectroscopy (EIS), a technique that analyzes the electrical response of a system subjected to a sinusoidal disturbance in order to probe its physicochemical properties, this study determined an optimal molar ratio of 1:7 between ethylene glycol (EG) and potassium iodide (KI). This composition significantly improves the electrochemical performance of the KI, EG, and I₂ electrolyte for photovoltaic applications. Four formulations with KI:EG molar ratios of 1:5, 1:7, 1:9, and 1:11 were synthesized. The amount of diiodine (I₂) was fixed at 0.1 mol% relative to the amount of KI. These electrolytes were then characterized by EIS. The series resistance (Rs), charge transfer resistance (Rct), diffusion resistance (Rw), CPE (constant phase element) parameter, and exponent (n) were extracted and compared. The results show that the formulation with KI:EG = 1:7 has the lowest Rct (3.054 Ω) and Rw (7.296 Ω) values, indicating optimal redox kinetics and improved ion transport within the electrolyte. This molar ratio corresponds to a minimum Rs value (5.612 Ω), indicating reduced series resistance. The mechanisms of solvation, viscosity, and ion diffusion are examined. This work, based exclusively on screening by electrochemical impedance spectroscopy (EIS), highlights the decisive role of solvent composition in electrolyte performance. It identifies an optimal molar ratio window that strikes a balance between redox efficiency and ion mobility, with a view to improving DSSC performance.