ABSTRACT Semi‐organic single crystals have gained significance in device fabrication due to their enhanced physicochemical properties and optical non‐linearities. A novel amino acid single crystal of L‐Cysteine Potassium Chloride (LCPC) was synthesized in a 1:1 ratio using slow evaporation. The structural analyses, such as SXRD, SEM‐EDS and FTIR, confirmed that the crystal belonged to the triclinic system, with bothL–cysteine and Potassium chloride incorporated in it. The LCPC single crystal has an energy bandgap of 3.647 eV, and its various optical constants were deduced from a UV–vis–NIR study. Photoluminescence analysis revealed electronic transitions of the crystal and could be applied in blue–violet light‐emitting diodes and laser devices. Through Vickers microhardness calibrations, the crystal falls under a soft material with considerable mechanical strength. Thermal studies using DTA showed a sharp endothermic peak at 230.82°C, while TGA indicated weight loss and helped to determine activation energy, confirming relatively good thermal resistance. Due to its high average specific capacitance of 557.51 F/g, it could be optimisable in practical supercapacitors. The crystal also exhibited SHG of about 0.657 times compared with the standard KDP crystal, and third‐order optical non‐linearities were studied using z‐scan and its probable applicability in NLO devices.
ABSTRACT In this work, the growth mechanisms of Si 1‐x Ge x and (Si 2 ) 1‐x (GaP) x solid mixture crystals, based on Si, Ge, and GaP nanoclusters, are considered, and quantum‐chemical calculations are performed. Quantum chemical calculations determine the stable isomers of nanoclusters and their corresponding theoretical total energies, Gibbs free energies, and entropy changes. This study investigates the composition of the crystals and concludes that Ge is most likely present in the atomic and Ge 2 states in the silicon crystal lattice, in the Si 5 and Si 20 states in the Ge crystal lattice, and in the Si 2 state in the GaP crystal lattice. Energy‐dispersive X‐ray and ATR‐FTIR spectroscopy confirm the chemical composition and bonding of the experimentally obtained crystals.
ABSTRACT Metal halide perovskite has shown great potential for X‐ray detectors due to their superior properties such as high X‐ray attenuation coefficients and large charge carrier mobility‐lifetime (μτ) product. Compared with the widely investigated polycrystalline thin films, perovskite single crystals without grain boundaries possess lower trap density and better optoelectronic properties, which results in higher sensitivity and lower detection limits for X‐ray detection. In this review, the recent progress of single‐crystal perovskite growth methods and X‐ray detector application are summarized, followed by a detailed description of the composition engineering of single‐crystal perovskites for X‐ray detection. Finally, a discussion about the challenges and perspectives in the development of perovskite single‐crystal X‐ray detectors is presented.
ABSTRACT Hydroxyapatite (HAp) nanostructures doped with different concentrations of europium (HApEuX%) were synthesized using microwave‐assisted hydrothermal methods. Their structural, vibrational, morphological, photoluminescent, and elemental compositional properties were characterized by x‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high‐resolution scanning electron microscopy (HRSEM), photoluminescence spectroscopy (PL), x‐ray fluorescence (XRF), and energy‐dispersive x‐ray spectroscopy (EDS). XRD analysis showed that the hexagonal HAp structure was preserved after Eu addition, with small variations in the lattice parameters. SEM images show that Eu addition produces increasingly heterogeneous morphologies, with shorter fibers, plate‐like structures, and aggregates. Furthermore, the samples exhibit the characteristic 5 D 0 → 7 F 0 transition observed at 578 nm in the photoluminescence spectra. The characteristic Eu 3 + emission bands confirm the presence of optically active Eu 3 + environments. The results demonstrate Eu‐dependent structural, morphological, and luminescent changes, supporting their future evaluation as luminescent bioceramics.
ABSTRACT Ga 0.9 In 0.1 Sb crystals (27 mm diameter, 90 mm length) were prepared with a [110] oriented GaSb seed crystal through the traveling heater method (THM), and the effects of the melt zone movement rate on the structures and photoelectric properties were investigated. The crystallization quality and the photoelectric properties of the crystals initially improved and then declined with the melt zone movement rate increased from 0.5 mm/h to 1.5 mm/h. When the movement rate was 1.0 mm/h, the crystallization quality and the photoelectric properties were optimal, the crystal's dislocation density (1.51× 10 3 cm −2 ) and radial segregation (0.032 mol%/mm) got their own lowest values, while its carrier concentration (1.57 × 10 18 cm −3 ), carrier mobility (1.71× 10 3 cm 2 /(V•s)), and infrared transmittance (55%) got their own highest values. However, when the rate was 0.5 mm/h, the crystallization quality and photoelectric properties were the worst, the dislocation density got the maximum 2.98 × 10 3 cm −2 , the radial segregation got the maximum 0.074 mol%/mm, while the carrier concentration got the minimum 1.37 × 10 18 cm −3 , and the carrier mobility got the minimum 1.57 × 10 3 cm 2 /(V•s).
