The paper analyzes the main characteristics of a new dynamic capacitor, which is a surface MOS-photovaricap, which is used as a modulating element when detecting signals from high-resistance sensors. Surface MOS-photovaricapes were made on high-resistance p-type silicon substrates with a thin insulating layer of SiO2 and a semitransparent metal electrode. Capacitance modulation during transimpedance conversion was carried out by LED lighting photovaricape in the optocoupler, which led to the appearance of an alternating voltage on the load resistor, which was subsequently amplified and registered. The results show that MOS-photovaricapes can be effectively used when measuring small constant and slowly changing currents and voltages from high-resistance sensors. This approach allows you to use this electrometric amplifier to register values slowly changing concentrations of gas, various types of radiation and types of particles, etc.
Studies on the synthesis of high-purity materials have shown that cerium oxide-doped zinc and zirconium silicate nanopowders can be used as pigments for solar reflectors in spacecraft. This has created the need to investigate their radiation resistance. The hydrothermal microwave-assisted synthesis of pure and cerium-doped zinc orthosilicate and zirconium silicate is described. The elemental composition of the materials was determined by instrumental neutron activation analysis. The paper presents the results of simulations of radiation effects on modified composite thermal-control coatings based on cerium-doped zinc orthosilicate (willemite) and zirconium silicate (Zn2SiO4:Ce and ZrSiO4:Ce). The theoretically predicted power-law dependence of the energy spectrum of atoms (ions) that acquired excess kinetic energy is consistent with the simulation results when only Coulomb scattering is taken into account during radiation exposure. The simulations also yielded the probabilities of defect formation in the crystals. Proton irradiation was found to produce the most severe damage to the crystal structure. The damaging effect of electrons is 4–7 times weaker, while that of neutrons is more than 70 times weaker. The simulation code is based on the GEANT4.11 software package.
The results of an experimental study of fabricated monolithic perovskite/silicon tandem solar cells with a nanostructured black silicon interlayer are presented. It is shown that the integration of a black silicon layer with an optimal thickness of 530 nm leads to an increase in power conversion efficiency from 26.2 to 27.8
The study investigates the effect of an ultrasonic field on the synthesis of natural carbonado-type polycrystalline diamond in a toroidal high-pressure chamber under constant pressure, temperature, and holding-time conditions. A method for introducing ultrasound into a toroid-type high-pressure apparatus was developed, ensuring the pressure–temperature parameters (P, T) required for carbonado synthesis. The proposed configuration provides acoustic excitation of both the rod and the graphite, implementing an axial waveguide energy-transfer mode and maximizing radial diffusion processes. An optimal range of amplitudes (1–1.5 μm) and frequencies (200–300 kHz) was determined, resulting in up to a 50
We studied the generation of high-order harmonics in hexagonal graphene quantum dots interacting with an intense linearly polarized electromagnetic wave. We used the tight-binding mean-field approximation to account for the many-particle Coulomb interaction. Our detailed analysis of the spectrum reveals the multiphoton resonant nature of harmonic generation, shedding light on the underlying quantum processes. The obtained results show that a 96-atom quantum dot exhibits a significant increase in high-order harmonic emission compared to the previously discussed graphene quantum dots.
