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Research on the semiconductors available for thermal neutron detection is of great significance for the development of thermal neutron detection technology and alleviating the dependence on rare 3 He resources. Hexagonal boron nitride (h- 10 BN) materials have attracted wide attention in the thermal neutron detection field because of their higher 10 B content and unique two-dimensional layered lattice structure. Based on the metal organic chemical vapor deposition (MOCVD) method, a 70 μ m h- 10 BN semiconductor detector was fabricated and experimentally studied. The product of the carrier mobility and lifetime ( μ τ ) of the semiconductor was 1.62 × 10 - 7 cm 2 /V. The time response of the detector was less than 12 ns, and the charge collection efficiency (CCE) was more than 90%. The effects on detection performance of the electric field distribution were studied. At 700 V, the maximum depth at which charges were able to be collected was approximately 50 μ m . The energy spectrum of the h- 10 BN to thermal neutrons was observed with distinct peaks. The results indicate that h- 10 BN has great potential in thermal neutron detection due to its high reaction section, compact volume and short trapping distance. [ABSTRACT FROM AUTHOR]

Herein, we report the details of the synthesis and crystal growth of a lead-free perovskite derivative Cs2TeI6 crystal, which reveals long-term environmental stability. The synthesis process is optimized to obtain pure Cs2TeI6 polycrystals, and to eliminate the formation of residual CsI resulting from high vapor pressure. Subsequently, the Cs2TeI6 single crystal with dimensions of Φ10 mm × 55 mm is grown by the vertical Bridgman method. The as-grown 0-D structural Cs2TeI6 crystal exhibits a high resistivity of 9.92 × 1011 Ω cm, and resulting mobilities of 4.03 ± 0.33 cm2 V−1 s−1 and 9.40 ± 0.45 cm2 V−1 s−1 for electrons and holes, respectively. The Au/Cs2TeI6/Au device shows a good response for optoelectronic and X-ray detection, with a relatively high X-ray sensitivity of 27.8 μC Gy−1 cm−2 and a low detection limit of 72.5 nGy s−1. [ABSTRACT FROM AUTHOR]

Ion migration in halide perovskite materials usually brings an intractable problem in the working stability of solar cells and photoelectrical detectors. The mechanism of ion migration and its impact on physical properties are still open questions. In this work, the ion migration behavior in solution-grown CsPbBr3 crystals was observed by the hysteresis in current–voltage curves and the temperature dependent reversed current–time measurements. Defect proliferation phenomena (new defects of [VCs]− and [PbBr]2+) originating from ion migration were verified by thermally stimulated current spectroscopy. Our results also give evidence that Cs+ ions also participate in the process of ion migration except the widely considered Br− ions. Furthermore, the photoelectric properties of the CsPbBr3 device were found to be seriously deteriorated after the ion migration. Our work demonstrates the strong correlation between the ion migration and physical properties in halide perovskites. [ABSTRACT FROM AUTHOR]

ZnO:Ga (GZO), as well as other band-edge luminous materials, exhibits fast time response properties, which makes it suitable for application as an ultraviolet scintillator for transient radiation detection. However, due to the serious self-absorption problem and low external quantum efficiency, the luminescence intensity cannot be intensified by increasing the volume of the crystals. To alleviate this problem, CsPbBr 3 quantum dot (QD) films were used to enhance the radioluminescence (RL) intensity of GZO. The effects of CsPbBr 3 QD films on the emission spectrum, intensity and angular distribution were experimentally analyzed under three different modes, namely, coating on the imaging surface, incident surface and both surfaces. The CsPbBr 3 QD film on the imaging surface could change the external quantum efficiency and luminescence angular distribution of GZO via its various surface morphologies. When CsPbBr 3 QD films were coated on both surfaces, the luminescence intensity reached 2.43 times that of GZO, while the proportion of emitted light from GZO was less than 6 %. Based on the experimental results, the principle of the enhancement and the difference among the three coating modes were discussed. The enhancement caused by CsPbBr 3 QD films on GZO was considerable and could be simply duplicated on many other materials, expanding their application in the field of detection and imaging. • Radioluminescence intensity of ZnO:Ga can be enhanced by coating perovskite films. • Scintillation performance of CsPbBr 3 QD film-coated ZnO:Ga was investigated. • Tuning the angular distribution by CsPbBr 3 QD film is beneficial for X-ray imaging. [ABSTRACT FROM AUTHOR]

Gamma detectors consisting of lanthanum bromide (LaBr 3) scintillator and silicon photomultiplier (SiPM) have extensive applications in various scientific fields. Accurate gamma energy measurement depends on accurate calibration of these detectors. While some studies have attempted detector self-calibration based on the natural background of LaBr 3 , these methods are limited to specific LaBr 3 crystals and lack generality. To address this limitation, this paper proposes a self-calibration method that solely utilizes the natural radioactivity of 138La. By solving for the maximum similarity between the test background from measurement and the standard spectrum obtained from the Geant4 simulation, the detector is effectively calibrated. Furthermore, the application of a series of energy spectrum processing algorithms simplifies the solution complexity of the maximum similarity problem. Experimental results from four different crystals at varying temperatures demonstrate calibration errors of less than 0.8% at 662 keV, highlighting the method's broad applicability and accuracy. Besides, the influence of the background measurement time and the natural environmental background on the self-calibration method are discussed in detail, further illustrating the value of the application. [ABSTRACT FROM AUTHOR]

In order to improve the temporal response of SiC-HPMTs, a new SiC detector with a faster time response (leading edge 1.5 ns, FWHM 4 ns) was developed for constructing an improved SiC-HPMT. Then the properties of the improved SiC-HPMT were studied in detail. Compared with those of the previous SiC-HPMT, the temporal response of the improved SiC-HPMT, with a leading edge of about 2 ns and a FWHM of less than 5ns was effectively improved. The maximum linear current that exceeded 630 mA depends on both the accelerating and focusing voltage (V a) and the bias voltage (V SiC) of the SiC detector, but has a strong dependence on V a. The scintillation detector comprised of the improved SiC-HPMT and an EJ228 scintillator can accurately obtain the multiple peaks characteristic of the pulsed X-ray source, which indicates that the improved SiC-HPMT can well satisfy the requirements for measuring the time information of fast pulsed radiation fields. In addition, the SiC-HPMT should be placed at the position that deviates from the radiation beam to avoid the direct irradiation on the SiC detector. The improved SiC-HPMT will further expand its application in pulsed radiation field measurements and become a supplement for existing photoelectric detectors. [ABSTRACT FROM AUTHOR]