Since the discovery of X-rays by Rntgen in 1895, radiation detection technology have developed rapidly and have been widely used in many fields such as medical imaging, security inspection, industrial non-destructive testing, nuclear safety monitoring, resource exploration, basic science and space science. In terms of detection materials and working principles, radiation detectors can be divided into gas detectors, scintillator detectors and semiconductor detectors. This article focuses on semiconductor detectors, starting from the interaction between various radiation and semiconductor materials, as well as the working principle and signal processing process of semiconductor detectors, and discusses the performance requirements and main points of detector design of semiconductor radiation detectors in different types of radiation and different application requirements. The performance and research progress of semiconductor materials in the field of radiation detection are reviewed according to the order of element family.

The development of perovskite materials in the fields of solar cells and photoelectric detection in recent decades has promoted the relevant materials research in nuclear radiation detection. It is of great scientific challenging to perform compositional design rationally and explore the characteristics of this family of materials by the virtue of their greatly diversified structural tolerance. To optimize their radiation detection performance, the device configuration should be specifically designed in various application scenarios according to the feature of each perovskite semiconductor. This review summarizes the materials characteristics and radiation detection properties of melt growth perovskite semiconductors from the viewpoint of different dimensionality and device design. This review shall provide a reference for the future development of perovskite semiconductors in nuclear radiation detection.

Scintillation crystal materials can be used in the detection of X-rays, γ-rays, neutrons and other high energy particles. After more than 100 years of development, the detection and imaging technology which take scintillating crystals as the core have been widely used in nuclear medicine, high energy physics, safety inspection, industrial nondestructive inspection, space physics and nuclear prospecting. With the further research and development of scintillation crystal materials, the better halide scintillation crystals such as LaBr3∶Ce on the market are gradually unable to meet the needs of development due to their high production cost, anisotropy and brittleness. At the same time, perovskite-type scintillation crystal materials have gradually entered people’s vision because of their easily improved deliquescence, lower production cost, easily adjusted growing conditions and good scintillation performance. In this paper, the crystal structure, property, growth method, development trend and application prospect of perovskite-type scintillation crystal materials ABX3 (A+ is Cs+, B2+ is part alkali-earth metal ions, X- is non-fluorine halogen ions) and K-based perovskite scintillation crystal materials are introduced emphatively. By doping some rare earth elements and improving the growth process, perovskite-type scintillation crystals with high light yield, good energy resolution and low cost can be widely used in the market.

Cerium-doped lutetium-yttrium oxyorthosilicate (LYSO∶Ce) crystals show excellent scintillation properties, and has been widely used in the filed of nuclear medicine, high-energy physics and safety inspection. The crystal structure, luminescent mechanism, main problems in the crystal growth and the possible direction of development of LYSO∶Ce scintillation crystals are reviewed in this paper. Furthermore, the common issues with corresponding solutions in the crystal growth of LYSO∶Ce are summarized, and further the space occupation of Ce3+ ions and the relationship between Ce4+ ions and scintillation properties are discussed. In addition, the latest research results from our groups in LYSO∶Ce crystal growth are displayed and the dimension of 95.42 mm×200 mm of LYSO∶Ce scintillation crystal was grown using medium frequency induction furnace.

The decay time of magnesium tantalate (Mg4Ta2O9) crystal is shorter than that of CdWO4 crystal, and its light yield and energy resolution are slightly higher than that of CdWO4 crystal respectively. Its afterglow is 0.01%/3 ms as low as that of CdWO4. In addition, the Mg4Ta2O9 crystal has no toxic elements, and will be one of the best candidate materials in the field of container security inspection for replacing CdWO4 crystal which containing toxic element Cd. The research progresses in the structural properties, crystal growth, scintillation properties and doping modification of Mg4Ta2O9 crystals are reviewed. The research show that Mg4Ta2O9 doping with Zn2+ or Nb5+ ions can significantly increase its light yield.

Cs2LiLaBr6∶Ce(CLLB∶Ce)crystal has excellent neutron-gamma dual readout performance, while its application bottleneck is to grow single crystals with large size and high optical quality. In this study, non-stoichiometric ratio was used to avoid the phase region of in-congruent CLLB∶Ce. By improved Bridgman furnace, optimizing the temperature field and reducing the lowering speed, the constitutional supercooling was overcame and the stability of the growth interface was maintained during the crystal growth process. 1-inch diameter CLLB∶Ce crystal ingot was obtained, the length of the equal diameter transparent part is 40 mm, the proportion of single crystal increases from 52% to 79%, and the optical transmittance in the visible light region is above 70%. The energy resolution of CLLB∶Ce is about 3.7% under 137Cs excitation while the Figure-of-Merit of CLLB∶Ce is about 1.42 under 252Cf excitation. This shows good properties for discriminating gamma-ray and neutron.

CdZnTe detectors play an important role in international astronomy research. In this paper, the spectra response of CdZnTe planar detector for γ-ray was numerically simulated using GEANT4 Monte-Carlo simulation toolkit, and the influence of the factors, such as transport properties of electrons and holes, applied bias voltage, thickness of detector and other factors were studied. The calculated results show that when the charge collection efficiency (CCE) of electron is high, the dependence of energy resolution on the ratio of electron and hole mobility-lifetime product ((μτ)e/(μτ)h) is strong, and the resolution increases with the decrease of the ratio. The energy resolution and CCE of carrier can be improved by raising up the bias. When the CCE of electron is high, increasing thickness can weaken the hole signal contribution to the total induced charge, and improve the energy resolution. The value of (μτ)eE/d can be used to evaluate CCE of planar CdZnTe detectors for rays of low energy, and the corresponding relationship was calculated.

Cadmium manganese telluride (CdMnTe) is an excellent room temperature nuclear radiation detector material, which can be used in environmental monitoring and industrial non-destructive testing. A room temperature planar detector with a size of 10 mm×10 mm×2 mm was fabricated using In doped Cd0.9Mn0.1Te crystal grown by Te solvent Bridgman method. The spectroscopy responses of CdMnTe detectors were investigated by irradiation of γ-ray from 241Am@59.5 keV source. By characterizing parameters of infrared transmittance, resistivity and energy spectrum response, the quality, electricity and detector performance of CdMnTe crystal were comprehensively evaluated. The results show that the infrared transmittance of the wafer are above 55%, up to 60%. The leakage current under 100 V bias voltage reduces from 9.48 nA to 7.90 nA after wet passivation. The resistivity after wet passivation is 2.832×1010 Ω·cm. Under the reverse bias of -400 V, the energy resolution of CdMnTe detector for 241Am@59.5 keV γ-ray source before and after passivation is 13.53% and 12.51%, respectively, and the electron mobility lifetime product after passivation is 1.049×10-3 cm2/V. The variation of energy resolution with voltage was studied. When the bias voltage is no more than 400 V, the energy resolution of the detector is mainly determined by the carrier collection efficiency. While when the bias voltage is more than 400 V, the energy resolution is affected by the leakage current of the detector. The research results show that the CdMnTe crystal grown by the Te solvent Bridgman method has good crystal quality, and the resistivity and electron mobility lifetime product can meet the requirements of detector preparation.

X-ray detection is of great significance for medical diagnostics, security inspection, and homeland security. The fabrication of a high-sensitivity X-ray detector can reduce the X-ray dose, especially in medical and security inspections. In this paper, the high-quality CsPbBr3 single-crystal film was prepared by a space-confined method. Then an X-ray detector with good performance based on the film were fabricated. The morphology, thickness, composition, and orientation of the films were analyzed by the polarizing microscope, scanning electron microscope equipped with EDS, and EBSD detector. It is found that the prepared single-crystal films have a flat, smooth surface, uniform element distribution, and homogeneous crystal orientation. The detector has high resistivity of 7.23×108 W·cm and an extremely high sensitivity of 2 610 μC·Gy-1·cm-2.

The large size and high quality inorganic metal halide perovskite Cs3Bi2I9(15 mm×50 mm) single crystal was successfully prepared by Bridgman method. The crystal belongs to the hexagonal system (P63/mmc) at room temperature and the parameters are a=b=0.840 nm, c=2.107 nm. The density of Cs3Bi2I9 is 5.07 g/cm3 and the melting point is 632 ℃. The crystal was characterized by powder X-ray diffraction, UV-Vis-NIR diffuse reflectance spectra and I-V test. The device structure of Au/Cs3Bi2I9/Au is constructed to measure the carrier ability of Cs3Bi2I9 crystal by the time of flight (TOF) technique. The electron mobility of Cs3Bi2I9 crystal is obtained approximately of 4.33 cm2·V-1·s-1. The carrier mobility life product (μτ) of Cs3Bi2I9 crystal is obtained ~8.21×10-5 cm2·V-1 by the Hecht equation, with the energy resolution of 39% at 500 V.

CsPbBr3 is a promising material for high-performance high-energy radiation detectors with high detection efficiency and good stability. In the ingredient stage of preparing the CsPbBr3 single crystal by the vertical Bridgman technique, the oxygen will adsorb on the surface of raw materials, and gather above the sealed crucible after melting, if the contact between the raw material and the oxygen cannot be effectively isolated, and results in a gradually darker color of the single crystal along the growth direction. The color change does not change the band gap of the CsPbBr3. The electrical performance test of the upper end section of CsPbBr3 single crystals reveals that the resistivity gradually decreases, and the trap density and carrier mobility gradually increases from the center to the outside of CsPbBr3 single crystals. But the responsiveness to X-rays is unchanged from the center to the outside of CsPbBr3 single crystals. This paper contributes to studies on the growth of high-quality CsPbBr3 single crystals.

Metal halides low-dimensional perovskites have highly efficient luminescent properties and shown great potential as scintillators for radiation detection applications. Herein,single crystal of all-inorganic zero-dimensional Cs3Cu2Br5 was grown by the Bridgman technique. The optical absorption, photoluminescence emission and excitation, time-resolved photoluminescence, and X-ray detection performance of Cs3Cu2Br5 were measured. The Cs3Cu2Br5 crystallized into orthorhombic system with a space group of Pnma. Under the excitation of X-ray, Cs3Cu2Br5 crystal has a broad emission peaking at about 467 nm originated from self-trapped exciton emission. The steady state light yield of Cs3Cu2Br5 is about 4 000 ph./MeV and its afterglow performance is comparable to that of BGO crystal.

Cs2LiYCl6∶Ce (CLYC∶Ce) is a new type of scintillation crystal with good energy resolution, high light output and excellent neutron/gamma discrimination ability. However, its complex composition results in many difficulties for crystal growth. In this paper, five different CLYC crystals with different composition ratios of LiCl accounted for 57%, 60% and 63% (mole fraction) and CsCl to YCl3 ratios of 1.9∶1 and 2.1∶1 were grown using the vertical Bridgman method. It is found that optimal proportion for high quality CLYC is 60% LiCl, where the volume ratio of transparent CLYC phase to the total ingot is the largest. Changing the ratio of CsCl to YCl3 has no obvious positive effect on crystal growth. The energy resolution of 5 mm×5 mm×5 mm and 25 mm×10 mm samples excited by 137Cs is 4.8% and 5.6%, respectively. The scintillation decay time of CLYC crystal under 662 keV gamma-ray excitation is 17 ns, 436 ns and 3 603 ns.

Cs2LiYCl6∶Ce(CLYC) is a novel scintillation crystal with the capability of neutron and gamma-ray detection. It can be used in the field of neutron and gamma-ray detection. The CLYC scintillation crystal with 95% enrichment of 6Li was grown by the vertical Bridgman method. After processing and moisture-proof packaging, a housed sample of 50 mm×50 mm CLYC scintillation crystal was obtained. 4.22% energy resolution is measured at 662 keV of 137Cs gamma rays. Neutron-gamma discrimination is also achieved. The figure of merit (FOM) of pulse shape discrimination (PSD) measured with a 252Cf neutron source is 3.45. With its excellent performance, CLYC scintillation crystal is expected to replacement for Helium-3 gas in the field of neutron detection, and can be used as the preferred material for n/γ dual detection. So CLYC crystal can be used in neutron radiation detectors, radioisotope identification instruments, personal radiation dosimeters, and other neutrons-gamma detection.

The effect of different reflector packaging materials and different coupling modes with Si-PM on the light output and energy resolution of Ce∶GAGG and CsI(Tl) scintillation crystals were studied. The transmittance and decay time of Ce∶GAGG and CsI(Tl) scintillation crystals were compared. The experimental results show that the light collection efficiency of Ce∶GAGG and CsI(Tl) scintillation crystals can be improved by optimizing the reflector material and coupling mode. The light output, energy resolution, transmittance and decay time of Ce∶GAGG scintillation crystal are better than those of CsI(Tl) scintillation crystal. The test shows that the best energy resolution of 137Cs radiation source is 4.89% at 662 keV for the Ce∶GAGG crystal sample that encapsulated with TiO2 reflector material and coupled with silicone grease.

In order to satisfy the requirement of the time-of-flight positron emission tomography (TOF-PET), the Ce∶LYSO scintillator should have higher light output, shorter decay time and faster rise time. The transparent and inclusions-free Ca∶Ce∶LYSO scintillation crystal with size of 100 mm×100 mm was successfully grown by frequency induction Czochralski method. The transmittance of the prepared crystal tested by UV-Vis spectrophotometer is close to the theoretical value, indicating its excellent quality. After cutting, grinding and polishing, the pulse height spectrum and decay time of the Ca∶Ce∶LYSO scintillation crystal were tested respectively. The measured light output, energy resolution and decay time are 33 962 ph/MeV, 8.6%, 36.70 ns, respectively, which shows its superior scintillation properties than Ce∶LYSO. The inhomogeneity of relative light output and energy resolution of axial sampling are ±2.4% and ±9.4%, and those of the tail-radial sampling are ±1.18% and ±6.8% respectively, which proves the crystal has good uniformity.

Novel cerium doped (Gd0.99-xYxCe0.01)2Si2O7 (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7) (GYPS∶Ce) scintillation crystals were grown by optical floating zone method, and phase identifications were carried out by X-ray diffraction (XRD). It belongs to orthorhombic of Pna21. Their photoluminescence (PL) and scintillation properties of as-grown crystals were characterized through vacuum ultra-violet (VUV) excitation and emission spectra, PL decay curves, X-ray excitation luminescence (XEL) spectra, γ-ray pulse height spectra. The emission peaks of VUV and XEL spectra all locate around 360 nm corresponding to 5d→4f transition. The PL decay time of as grown samples are in the range of 29.1 ns to 32.9 ns. The scintillation decay time components are in the range of 28 ns to 68 ns and 256 ns to 583 ns. There has energy transfer behavior of Gd3+→Ce3+ in crystal.

The single crystals of Yb3+-doped and Si4+ co-doped Y3Al5O12 (YAG) were grown by the Czochralski method. Both crystals belong to the cubic system with the Oh10-Ia3d space group. The addition of Si4+ does not change their crystal structure, but changes the luminescent ions valent. The absorption spectrum manifests that the substitution of Al3+ by Si4+ leads to the transformation of Yb3+ to Yb2+ for the charge balance, and then reduces the luminous intensity of Yb∶YAG. The X-ray and γ-ray excited luminescence (XEL) measurement shows that the luminous intensity of Si4+ co-doped Yb∶YAG is about 63% and 40% of Yb∶YAG, respectively. Additionally, because of the isotope of Yb, Yb∶YAG can even be excited by neutrons with nuclear reaction, the charge particles cause secondary reactions to produce fluorescence. The fluorescence intensity is still determined by Yb3+, thus the sensitivity for neutron is also reduced by Si4+ co-doping.

Rare earth scintillation eutectic is a kind of radioluminescence material including two crystallographic phases with different refractive index prepared by directional solidification. The refractive index of the scintillator phase doped with active ions is higher than that of the matrix phase. Under the irradiation of high-energy rays, the scintillation light can be generated in the scintillation phase, and then the scintillation light is transmitted and output in total reflection at the interface between scintillator phase and matrix phase, thus effectively improving the spatial resolution of radiation detection imaging through directional propagation. In this work, 1.0%(atomic fraction) Ce∶GdLu2Al5O12/Al2O3eutectic with the size of 3 mm×117.0 mm was successfully grown by micro-pulling-down method. The 3 mm×2.0 mm thin eutectic slices were obtained by cutting and polishing, and then were used to be tested for microstructure, energy spectrum and fluorescence properties analysis. It is confirmed that the eutectic is composed of Ce∶GdLuAG and Al2O3 by XRD, SEM and EDS determination. There is a certain ordered arrangement in the growth direction. The fluorescence spectra show that the eutectic material has energy transfer between Gd3+-Ce3+, and has a typical Ce3+ radiation transition, in which the double broad emission peak is the strongest at 560 nm. In addition, according to the effects of pulling speed on the emission peak intensity, peak position and fluorescence lifetime, the growth rate was optimized to be 4.0 mm/min.

Binary ordered eutectic materials which have two separated crystallographic phases with different refractive index can reduce light scattering and possess light guiding properties, which may be used in high spatial resolution imaging detectors. In this work, the ordered eutectics GdAlO3∶Tb3+-Al2O3 with a diameter of 3 mm were grown by micro-pulling-down method according to directionally solidified principle. The internal structure of obtained eutectics was determined by SEM and elemental analysis. It was found that the GdAlO3∶Tb3+ crystal fibers were well aligned in the matrix Al2O3 crystallographic phase and the diameter of GdAlO3∶Tb3+ crystal fibers can be adjusted by pulling-down speed during crystal growth process. The faster the pulling-down speed is, the smaller the crystal fiber becomes. At the same time, the radioluminescence properties of GdAlO3∶Tb3+-Al2O3 eutectic samples were determined. The GdAlO3∶Tb3+ crystal fibers can convert X-rays to green lights and the emitted green lights are transported along the fiber direction by total reflection mode, which can overcome resolution reduction caused by light scattering and have potential application for X-ray detection.

p-Terphenyl is a common organic scintillator, which is usually used as the luminescent material in scintillation counters. The p-terphenyl scintillation crystal has the characteristics of high neutron detection efficiency and not easy to deliquesce, which makes it have a broad prospect in practical applications. In this paper, the vertical Bridgman method was used, and the 12 mm×30 mm p-terphenyl scintillation crystal has grown using a single layer ampoule. The growth temperature of the crystals was determined by differential thermal test. The crystalline powder were measured by X-ray diffraction spectra, rocking curve, FT-IR spectra, fluorescence spectra and Raman spectra. The X-ray diffraction results show that the grown crystals are pure p-terphenyl phase. The rocking curve results show that the quality of the p-terphenyl crystal is good. FT-IR and Raman results show no significant shift in the peak positions, indicating that the low content of impurities in the crystals and no changement in the molecular chemical structure of the crystals. The absence of impurity peaks in the fluorescence spectra also indicates the presence of fewer impurities or crystal lattice defects in the p-terphenyl scintillation crystal.

A serious of lutetium stabilized gadolinium aluminum garnet transparent ceramics {(Gd, Lu)3Al5O12∶Tb, Eu} were prepared by co-precipitation method combining vacuum sintering process. Then the transparent ceramics with the thickness of 1 mm were polished. Crystal structure of transparent ceramic samples was characterized by X-ray diffraction and the optical property was characterized by fluorescence spectrophotometer and UV near infrared spectrophotometer. After the process of sintering ceramics at high temperature, the ceramic samples still maintain stable garnet phase. In the emission spectra obtained by UV excitation of different samples. 313 nm was selected as the excitation wavelength of transparent ceramics and the strongest emission peak can be obtained. The emission light from green light to red light can be adjusted. After 313 nm excitation, all transparent ceramic samples have a millisecond decay time of Eu3+at 543 nm and 591 nm emission wavelengths.