Al-doped zinc oxide (AZO) has attracted sustained interest as a low-cost, earth-abundant n-type transparent conducting oxide for solution-processed heterojunction photovoltaics. In the present work, undoped ZnO and AZO (2 mol% Al/Zn) thin films were deposited on p-CdTe by a sol–gel spin-coating route and examined as direct, CdS-free ZnO(AZO)/CdTe heterojunctions – a configuration for which experimental reports remain scarce. The structural, optical, electrical, and morphological responses were investigated by XRD, UV–Vis absorbance spectroscopy with first-derivative band-edge analysis, dark and illuminated J–V measurements with Cheung–Cheung diode-parameter extraction, and SEM. XRD confirmed the coexistence of zinc-blende CdTe and c-axis-oriented wurtzite ZnO, with Scherrer crystallite sizes of 27 ± 5 nm. The derivative absorbance maximum shifted from 3.31 eV (ZnO) to 3.33 eV (AZO). Under illumination, the AZO/CdTe device yielded Jsc ≈ 4.2mA·cm-2, Voc ≈ 0.43V, with n ≈ 3.1, Rs ≈ 28 Ω·cm2, Rsh ≈ 310 Ω·cm2, FF ≈ 27%, η ≈ 0.49%. SEM revealed a pinhole-free polycrystalline AZO overlayer (30–80 nm grains). The results establish a baseline characterization of buffer-free, solution-processed AZO/CdTe heterojunctions.
On Si (111) substrates with a diameter of 20 mm, continuous monocrystalline epitaxial layers of (Si2)1-x(GaN)x solid solutions were grown by liquid-phase epitaxy from a limited volume of a tin solution-melt. The grown films had n-type conductivity. An analysis of the X-ray diffraction pattern showed that the grown epitaxial film has (111) crystallographic orientation with evident single-crystal sings. The size of the film subcrystallites is ̴ 40 nm. Due to the replacement of paired Si atoms by a molecule consisting of Ga and N atoms, a slight bending of the film towards the perpendicular to the reflecting surface was observed. Coherently arranged nanocrystals of cubic (c - GaN) and hexagonal (h - GaN) modification of gallium nitride with a crystallite size of LGaN≈47 nm are formed in the crystal lattice of the epitaxial film.
This work presents a theoretical study of differential resistance and noise in tunnel diodes under combined optical, magnetic, and high-frequency electromagnetic fields. The tunneling current is modeled using the Tsu–Esaki approach with WKB approximation, while magnetic field effects are introduced via Landau quantization. Optical excitation leads to quasi-Fermi-level splitting and enhances the tunneling current, thereby modulating and smoothing the negative differential resistance (NDR) region. High-frequency fields further modify the barrier transparency, thereby affecting the device's dynamic behavior. Noise analysis based on shot noise and Fano factor shows that a high signal-to-noise ratio (SNR) can be maintained under external perturbations. A generalized multi-field model for n⁺–GaAs/AlGaAs heterostructures is proposed, demonstrating controllable tunneling dynamics, low noise, and stable operation in the sub-THz range. The results indicate strong potential for applications in high-speed optoelectronics and radiation-resistant space electronics.
This study investigates the distribution of Ti-6Al-4V alloy powder microparticles used in 3D printing under different discharge frequencies and NaCl electrolyte concentrations. This work analyzed the process of obtaining monodisperse Ti-6Al-4V alloy powders using the ECDM method. The results showed that an optimal NaCl electrolyte concentration of 30 g/L ensures stable plasma channel formation and a narrow particle size distribution. Regression analysis and low standard error values (0.00386–0.00834) confirm the process's high controllability. The effect of frequency on particle size was also investigated: at 3.2 kHz, the minimum average particle size of 16.598 µm was recorded, whereas increasing the frequency to 32 kHz increased particle size to 28.063 µm due to thermal accumulation. The results indicate that at both 3.2 kHz and 32 kHz frequencies, 58.24% to 68.89% of the produced powders fall within the 15–55 µm range required for PBF-LB/M technology. These findings demonstrate the suitability of the obtained powders for additive manufacturing technologies.
The integration of magnetic functionality into silicon remains a key challenge for the development of spintronic devices. In this work, we investigate the structural, electrical, and magnetic properties of Mn-diffused silicon fabricated via a two-step thermal diffusion process that enables controlled incorporation and redistribution of Mn within the Si matrix. Magnetic measurements reveal clear ferromagnetic behavior at room temperature, characterized by a well-defined hysteresis loop with finite coercivity and remanent magnetization. The temperature dependence of magnetization indicates a Curie temperature of approximately 360 K, confirming the stability of magnetic ordering above room temperature. Electrical transport measurements show a systematic evolution of carrier properties with increasing diffusion temperature, including a transition from p-type to n-type conductivity. This behavior is attributed to the activation of Mn-related donor states and defect complexes leading to compensation and overcompensation of boron acceptors. A strong correlation between carrier concentration and magnetic properties is observed, indicating the crucial role of free carriers in mediating magnetic interactions. Based on the combined experimental results, the observed ferromagnetism is attributed to a cluster-induced mechanism, in which Mn-rich regions act as localized magnetic centers coupled via carrier-mediated exchange interactions, consistent with an RKKY-type mechanism. These findings demonstrate that two-step thermal diffusion provides an effective route to tune both the electrical and magnetic properties of silicon, highlighting its potential for silicon-based spintronic applications.
