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Ce‐doped Cs2LiLaBr6 (CLLB) scintillator crystals, known for their superior neutron/gamma dual‐mode detection capability and exceptional scintillation properties, have garnered significant attention for both fundamental science and practical applications. The role of Ce3+ cations as luminescent centers is pivotal, influencing the scintillation properties as their concentration varies. While the effects of Ce3+ concentration on scintillation performance are well‐documented, the ramifications for crystalline structure remain less explored. In this study, high‐quality CLLB:Ce single crystals are fabricated(atomic packing factor of maximum doped Ce is 0.04%) using the vertical Bridgman (VB) method and subsequently characterized their crystalline structure by neutron diffraction, X‐ray diffraction (XRD), and elemental analysis. The findings reveal a correlation between Ce3+ concentration and the crystal cell parameters, presenting intriguing deviations from Vegard's law. Such observations suggest the potential presence of alternative defects, potentially Li+ interstitials, in CLLB:Ce. This work offers critical insights for advancing the understanding and optimization of CLLB:Ce scintillators. [ABSTRACT FROM AUTHOR]

Ternary chalcogenide PbGa2Se4 with high resistivity, photosensitivity, and excellent nonlinear properties, exhibits a potential application in optoelectronic and nonlinear optical devices. However, the preparation of large‐sized pure PbGa2Se4 crystals is challenging due to the presence of peritectic reaction L+α(Ga2Se3)→PbGa2Se4${\mathrm{L}} + {{\alpha}}({G{a}_2S{e}_3}) \to PbG{a}_2S{e}_4$ and a narrow homogeneity region. Here, a "quenching‐annealing" method (quenching at 850 °C in ice water, and then annealing at 650 °C for 250 h by reheating) is developed to eliminate the PbSe second phase during the synthesis. Subsequently, the PbGa2Se4 single crystals are successfully grown using chemical vapor transport (CVT) with the I2 as the transport agent. The resulting crystal exhibits the crystal structure belonging to Fddd space group with the lattice parameters of a = 12.7192 Å, b = 21.2831 Å, and c = 21.5226 Å. Additionally, it possesses a wide bandgap (≈2.26 eV), high resistivity (6.59 × 1012 Ω·cm), and defect density calculated via space charge limited current measurement (SCLC) as 2.46 × 1011 cm−3. Photodetectors based on these as‐grown crystals demonstrate exceptional photosensitivity along with a high detectivity (3.2 × 108 Jones). [ABSTRACT FROM AUTHOR]

All‐inorganic metal halide perovskite CsPbBr3 crystal is regarded as an attractive alternative to high purity Ge and CdZnTe for room temperature γ‐ray detection. However, high γ‐ray resolution is only observable in small CsPbBr3 crystal; more practical and deployable large crystal exhibits very low, and even no detection efficiency, thereby thwarting prospects for cost‐effective room temperature γ‐ray detection. The poor performance of large crystal is attributed to the unexpected secondary phase inclusion during crystal growth, which traps the generated carriers. Here, the solid–liquid interface during crystal growth is engineered by optimizing the temperature gradient and growth velocity. This minimizes the unfavorable formation of the secondary phase, leading to industrial‐grade crystals with a diameter of 30 mm. This excellent‐quality crystal exhibits remarkably high carrier mobility of 35.4 cm2 V−1 s−1 and resolves the peak of 137Cs@ 662 keV γ‐ray at an energy resolution of 9.91%. These values are the highest among previously reported large crystals. [ABSTRACT FROM AUTHOR]

Aluminum antimonide (AlSb) has a great potential application in electronic devices used at high temperatures. However, the properties of available AlSb crystals were still far away from the theoretical ones due to the high density of variant defects, especially point defects. Here, an improvement in optical transmittance and resistivity of AlSb was achieved by doping the as-grown AlSb with appropriate content of Te, through which the absorption of a spin split-off-heavy-hole band transition near 1.65 μm disappeared and the resistivity was increased from 102 to 106 Ω cm. It was suggested that the residual acceptors with the binding energy EA of 37.4 meV were compensated by a Te donor with ED = 71 meV in the AlSb:Te crystal, according to the evaluation of the competing recombination (e, A0) and (Te0, A0). An energy band model was proposed to describe the recombination process and the underlying mechanism. The photo-response of the high resistance AlSb:Te crystal, illuminated by a pulsed LED light in the visible light range, revealed that the ratio of photocurrent to dark current was 128, indicating a great potential application for room-temperature photo-detection. [ABSTRACT FROM AUTHOR]

Gamma/neutron dual detection has occupied significant territory in the field of homeland security and nuclear energy development. Cs2LiLaBr6 (CLLB) has shown both neutron/gamma dual-mode detection capability and excellent scintillation properties. Herein, we explored the Cs2LaBr5-LiBr phase diagram through powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) tests of synthesized polycrystalline materials. The Cs2LaBr5-rich side of the phase diagram is similar to a binary peritectic phase diagram, where the peritectic line (447 °C) extends to a LiBr content of 61%. The LiBr-rich side of the phase diagram resembles a binary eutectic phase diagram, where the eutectic point (395 °C) is located at 80% LiBr concentration. Guided by the phase diagram, CLLB ingots were designed to grow from the LiBr-rich side with different concentrations of LiBr. The scintillator properties of CLLB crystals were found to be deteriorated by the increasing defects with elevated LiBr contents. A concentration of LiBr around 55% was a preference for the growth of high-quality CLLB. A better understanding of the Cs2LaBr5-LiBr phase diagram benefits the growth of CLLB crystals and provides considerations for other halide double perovskites. [ABSTRACT FROM AUTHOR]

The heavy metal selenophosphate Pb2P2Se6emerges as a promising room-temperature X-ray/γ-ray detectors due to its high resistivity, robust radiation-blocking capability, and outstanding carrier mobility-lifetime product, etc. However, the high activity of phosphides poses significant impediment to the synthesis and single crystal growth. In this work, we have prepared high-quality Pb2P2Se6 single crystals with using the chemical vapor transport (CVT) method. The XRD analysis combined with EDS result confirmed the uniform composition of the resulting as-grown single crystals, while UV-Vis-NIR transmittance spectra revealed the bandgap of 1.89 eV. Selected area electron diffraction patterns indicated the crystal belonged to the P21/c(14) space group. Additionally, the Au/Pb2P2Se6/Au device is fabricated, which exhibits a robust X-ray response with a sensitivity of 648.61 μC·Gy-1·cm-2 at 400 V·mm-1 under 50 kVp. Notably, the device also excels in alpha particle detection, boasting a resolution of ~14.48% under a bias of 400 V bias. The hole mobility-lifetime product (µτ)h of Pb2P2Se6 is estimated to be ~2.58×10-5 cm2·V-1. The results underscore potential applications of Pb2P2Se6 crystal is in the field of the semiconductor radiation detectors., (© 2024 Wiley‐VCH GmbH.)

All-inorganic metal halide perovskite CsPbBr 3 crystal is regarded as an attractive alternative to high purity Ge and CdZnTe for room temperature γ-ray detection. However, high γ-ray resolution is only observable in small CsPbBr 3 crystal; more practical and deployable large crystal exhibits very low, and even no detection efficiency, thereby thwarting prospects for cost-effective room temperature γ-ray detection. The poor performance of large crystal is attributed to the unexpected secondary phase inclusion during crystal growth, which traps the generated carriers. Here, the solid-liquid interface during crystal growth is engineered by optimizing the temperature gradient and growth velocity. This minimizes the unfavorable formation of the secondary phase, leading to industrial-grade crystals with a diameter of 30 mm. This excellent-quality crystal exhibits remarkably high carrier mobility of 35.4 cm 2 V -1 s -1 and resolves the peak of 137 Cs@ 662 keV γ-ray at an energy resolution of 9.91%. These values are the highest among previously reported large crystals., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)