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This review provides a summary of the growth, progress, and characterization studies of benzimidazole single crystals and their derivatives. Various methods, including SEST, Vertical Bridgeman, and Sankaran Narayanan methods, were employed to grow organic nonlinear optical (NLO) single crystals of BMZ derivatives. The developed crystals underwent different characterization analyses such as UV-Vis-NIR spectroscopy, microhardness testing, and Second Harmonic Generation. The focus of this review is specifically on the advancement of the NLO characteristics of the BMZ single crystal. [ABSTRACT FROM AUTHOR]

In this article, we discuss the preparation of organic 2-chloro-5 nitroaniline (2C5NA) crystals and their different kinds of physical, chemical, and mechanical properties. The vertical Bridgman approach was used to effectively produce the bulk organic 2C5NA crystal. To produce a good-quality bulk crystal, the shape, dimensions, and cone angle of the ampoule were optimized. Also, the temperature profile was set for the 2C5NA crystal. The growth atmosphere and the lowering rate were identified to obtain a homogeneous mixture of the compounds and initiate the nucleation process. Single-crystal X-ray diffraction (XRD), powder XRD, proton Fourier transform nuclear magnetic resonance (FT-NMR), and Fourier transform infrared investigations were used to confirm the crystal structure, molecular structure, and presence of functional groups in the formed crystal. The formed crystal has a monoclinic crystal structure with the space group P21/c, according to single-crystal XRD analysis. The thermal stability and kinetic parameters were examined using thermogravimetric analysis and differential thermal curves. From dielectric analysis, the electrical conductivity and dielectric behavior of 2C5NA were investigated with variations in frequency and temperature. The organic 2-chloro-5-nitroaniline crystal demonstrates that the indentation size effect is observed in the Vickers micro-hardness test, which was also carried out. [ABSTRACT FROM AUTHOR]

To date, 3He gas has been commonly used to detect thermal neutrons because of their high chemical stability and low sensitivity to γ-rays, owing to their low density and large neutron capture cross-section. However, the depletion of 3He gas prompts the development of a new solid scintillator for thermal neutron detection to replace 3He gas detectors. Solid scintillators containing 6Li are commonly used to detect thermal neutrons. However, they are currently used in single crystals only, and their 6Li concentration is defined by their chemical composition. In this study, 6Li-containing eutectic scintillators were developed. CeCl3 was selected as the scintillator phase because of its low density (3.9 g/cm3); high light yield (30,000 photons/MeV); and fast decay time with four components of 4.4 ns (6.6%), 23.2 ns (69.6%), 70 ns (7.5%) and >10 μs (16.3%), owing to the Ce3+ 5d-4f emission peak at approximately 360 nm. Crystals of the CeCl3, LiCl and CaCl2 ternary eutectic were fabricated by the vertical Bridgman technique. The grown eutectic crystals exhibited Ce3+ 5d-4f emission with a peak at 360 nm. The light yield was 18,000 photons/neutron, and the decay time was 10.5 ns (27.7%) and 40.1 ns (72.3%). Therefore, this work demonstrates optimization by combining a scintillator phase and Li-rich matrix phase for high Li content, fast timing, high light yield and low density. [ABSTRACT FROM AUTHOR]

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In this work, the spectroscopic performances of new cadmium–zinc–telluride (CZT) pixel detectors recently developed at IMEM‐CNR of Parma (Italy) are presented. Sub‐millimetre arrays with pixel pitch less than 500 µm, based on boron oxide encapsulated vertical Bridgman grown CZT crystals, were fabricated. Excellent room‐temperature performance characterizes the detectors even at high‐bias‐voltage operation (9000 V cm−1), with energy resolutions (FWHM) of 4% (0.9 keV), 1.7% (1 keV) and 1.3% (1.6 keV) at 22.1, 59.5 and 122.1 keV, respectively. Charge‐sharing investigations were performed with both uncollimated and collimated synchrotron X‐ray beams with particular attention to the mitigation of the charge losses at the inter‐pixel gap region. High‐rate measurements demonstrated the absence of high‐flux radiation‐induced polarization phenomena up to 2 × 106 photons mm−2 s−1. These activities are in the framework of an international collaboration on the development of energy‐resolved photon‐counting systems for high‐flux energy‐resolved X‐ray imaging. [ABSTRACT FROM AUTHOR]

Abstract: Lithium tantalate, LiTaO3 (LT), single crystal growth by the vertical Bridgman (VB) technique is attempt for the first time. In the present VB‐LT technique, pure platinum crucibles are used in a furnace with a graphite heater and an argon atmosphere. One‐hundred percent solidified crack‐free VB‐LT crystals are successfully grown by composing the initial melts with exactly congruent compositions. The fundamental technical issues for VB‐LT growth are also clarified. [ABSTRACT FROM AUTHOR]

During the growth process of organic crystals, it is easy to induce thermal defects and impurities when using the conventional Bridgman technique. In the present study, a specially designed double-wall ampoule was used to solve this problem. High-quality p-terphenyl single crystals were successfully grown by the vertical Bridgman method with the improved ampoule. Powder X-ray diffraction analyses were performed to evaluate the crystallinity of the grown single crystals. Fluorescence spectrum studies show an enhancement of fluorescence properties due to the improvement in crystalline perfection. [ABSTRACT FROM AUTHOR]

We compared thermal stability, open-circuit voltage, short-circuit current, and fill factor values of single-crystal Cadmium telluride (CdTe) grown using the vertical Bridgman (VB) technique and doped with group V elements (phosphorus and arsenic), and group Ⅰ element (sodium), followed by an annealing process. The sodium-doped CdTe maintained a hole density of 1016 cm−3 or higher; after annealing for a long time, this decreased to 1015 cm−3 or less. The arsenic-doped CdTe maintained a hole density of approximately 1016 cm−3 even after the annealing process; however its bulk minority carrier lifetime decreased by approximately 10%. The phosphorus-doped CdTe maintained its properties after the annealing process, ultimately achieving a hole density of ~1016 cm−3 and a minority carrier lifetime of ~40 ns. The characteristics of a single-crystal solar cell were evaluated using a solar cell device that contained single-crystal CdTe with various dopants. The sodium-doped sample exhibited poor interfacial properties, and its performance decreased rapidly during annealing. The samples doped with group V elements exhibited stable characteristics even during long-term annealing. We concluded, therefore, that group V elements dopants are more suitable for CdTe single-crystal-based solar cell applications involving thermal stress conditions, such as space missions or extreme fabrication temperature environments. [ABSTRACT FROM AUTHOR]

InAsxSb1−x is an important material to fabricate detectors in the mid wavelength and long wavelength infrared region. The wavelength and the lattice constant for InAsxSb1−x can be tuned in the range of 6.8 µ m–3.5 µ m and 6.478–6.058Å by adjusting the arsenic composition. InAsxSb1−x crystals were grown by the vertical rotational Bridgman technique using GaAs (001) single crystal seed. Growth parameters such as temperature, period, ampoule design modification and cooling rate were analysed and used. A cooling rate of 0.25°C/hr is employed and the temperature of the growth region is carefully selected by suitably varying the temperature program/profile. Thermal pulse striations have been introduced inside the crystal during growth and etching technique was used to determine the real growth rate of the crystal. The chemical homogeneity and infrared transmittance analysis were carried out on the grown crystals. [ABSTRACT FROM AUTHOR]

In this study, group III–V compound semiconductor gallium antimonide (GaSb) crystal is grown by the vertical Bridgman technique. A (111) twinning is generated in the as‐grown crystal due to its polarity behavior as the GaSb crystal has a zinc‐blende structure. Hall effect measurements illustrate that the as‐grown GaSb crystal has n‐type semiconductor behavior among the whole temperature range, and the carrier concentration reaches the highest value of 3.27 × 1018 cm3 at 900 K. Thermoelectric behavior of GaSb crystals along the (111) plane is investigated. It shows the lowest electrical conductivity of 53.2 S cm−1 and the highest Seebeck coefficient of −470.0 µV K−1 at 700 K. However, the largest power factor of 13.7 µW cm K−2 takes place at 600 K. For thermal conductivity (k), the k value always decreases with increasing temperature, and the lowest k that occurred at around 900 K is about 7.44 W m−1 K−1. Finally, a maximum figure of merit of 0.082 is obtained at 700 K. [ABSTRACT FROM AUTHOR]

Crack‐free single crystals of 42°RY‐oriented lithium tantalate, 42°RY‐LiTaO3 (42°RY‐LT), are grown by the vertical Bridgman (VB) technique, using pure platinum bottomless crucibles to avoid cracking the seed crystal. The fundamental technical issues for 42°RY‐LT growth by the VB technique are clarified. [ABSTRACT FROM AUTHOR]