This paper proposes a rapid 15-min method for the alkaline etching of monocrystalline silicon surfaces using butyl alcohol as a surfactant. It is shown that, compared to isopropyl alcohol, the addition of butyl alcohol improves surface wettability and ensures more uniform anisotropic etching. It is shown that this results in a uniform and well-developed pyramidal structure, and the reflectance, due to multiple internal reflections of light between the pyramid faces, is reduced to 1–3
MXenes are a family of 2D transition metal carbides, nitrides, or carbonitrides having application in optoelectronics and spintronics devices due to their excellent hydrophilic nature, high surface area, 2D layered structure, functional groups, and properties including magnetic and optical. The present study focuses on the synthesis of 2D Ti3C2Tx MXene layers, NiFe2O4 nanoparticles, and Ti3C2Tx/NiFe2O4 composites followed by detailed analysis of temperature-dependent structural, optical, and magnetic properties describing the underlying physics as well. The formation of cubic NiFe2O4 nanoparticles and hexagonal 2D Ti3C2Tx MXene layers with decrease of crystallite size for pure from 21.7 to 11 nm, and 9.2 to 8.8 nm in composite was calculated from XRD studies, respectively. The morphological study displays multilayered, laminated, and high-quality accordion-like Ti3C2Tx sheets. The optical direct (2.9–3.7 eV) and indirect (2.87–3.34 eV) band gaps were calculated using the Tauc plot method. Various magnetic features were also analyzed at low temperatures up to 5 K for the composite annealed at 800 °C. Significantly large Hc (0.95–4.83 KOe) for composite has been observed confirming its ferromagnetic nature. Ms enhances with the decrease in temperature, and the exchange coupling was also observed which enhances for 250 K and then decreases with the decrease of temperature. These features emphasize the potential use of Ti3C2Tx/NiFe2O4 composites in optical and magnetic device applications.
This study investigates the effect of multiphase synergistic interactions in a PANI/MWCNT/PbS nanocomposite on the performance of an infrared (IR) detector operating at 940 nm. In addition, a comparative sample containing polyurethane (PU) was evaluated to examine its influence on the electrical stability of the sensing layer under temperature variations in the range of 5–35 °C. To this end, one-, two-, and three-component nanocomposites consisting of multi-walled carbon nanotubes (MWCNTs) and lead sulfide (PbS) nanoparticles embedded within a PANI matrix were synthesized and deposited as the active sensing layer. The structural and morphological characteristics of the prepared nanocomposites were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM observations revealed a relatively uniform distribution of the nanophases in the PANI matrix, which contributes to improved infrared absorption and enhanced optoelectronic interaction within the composite structure. Electrical characterization of the fabricated infrared detectors indicated that the CNT/PU composite exhibited the lowest electrical resistance, ranging from 17.1 to 15 kΩ, along with the highest thermal stability within the investigated temperature range. Meanwhile, the ternary nanocomposite (PANI/CNT/PbS) demonstrated the best sensing performance under infrared illumination, showing a maximum normalized resistance reduction of 29.2
This study synthesized ZnS/SnSx(x=1,2) composite sensing materials (S1) via a hydrothermal method and systematically evaluated their ammonia (NH3) sensing performance at room temperature under high-humidity conditions, using SnSx samples (S2) for comparison. XRD, SEM, TEM, HRTEM, and XPS analyses supported the formation of ZnS/SnSx heterostructures with a layered morphology. S1 exhibited a response value of 8.93 toward 100 ppm NH3 at 25 °C and 80
The multifunctional physical properties of the cobalt coordination single-crystal tetraaqua-bis((3-carboxy-5-(pyridin-4-yl)benzoate-κ1N)cobalt(II)] tetrahydrate (CPBC), C26H32CoN2O16, are systematically investigated. Although the crystal structure of CPBC has previously been reported, a comprehensive investigation combining its optical, nonlinear optical, piezoelectric, magnetic, electrical polarization and terahertz responses has not been presented within a single study. Single-crystal X-ray diffraction confirms that the crystals investigated here are consistent with the previously established orthorhombic non-centrosymmetric Fdd2 structure. High-resolution X-ray diffraction, UV–visible spectroscopy, second-harmonic generation, piezoelectric measurements, magnetic hysteresis, polarization–electric field analysis and terahertz time-domain spectroscopy were employed to establish correlations between the crystallographic framework and the experimentally observed physical responses. CPBC exhibits approximately 72
