Recently, three-dimensional (3D) halide perovskites were considered as Xray detection materials because of their high mobility, carrier lifetime, and absorption of Xray radiation. However, their detection sensitivity and instability at extreme conditions and environments still require optimization. In our present research work, we report using onedimensional (1D) inorganic halide perovskite CsPbI 3 crystals for stable X-ray detection. Remarkably, an X-ray detector made of CsPbI 3 has a high sensitivity of 2.37 mC•Gy −1 • cm −2 , which is an order of magnitude greater than that of detectors using 3D halide perovskites reported previously. The high-sensitivity X-ray detection of CsPbI 3 crystals is attributed to their high resistivity of 7.4 × 10 9 Ω•cm and large carrier mobility−lifetime product of 3.63 × 10 −3 cm 2 •V −1 . Our investigation demonstrates the quite promising applications of X-ray detectors made of the low-dimensional perovskite crystals.

Methylammonium (MA) lead hybrid perovskite single crystal recently received attention as a potential radiation detection material. Here, we report the MAPbBr 3 bulk crystals grown by the modified antisolvent vapor-assisted crystallization method. The growth rate is determined by diluting the antisolvent, which results in the average size of MAPbBr 3 crystals to significantly increase from 2 × 2 × 1 to 15 × 15 × 5 mm 3 . The morphology evolution of MAPbBr 3 crystals, which is contributed by the growth anisotropy, has been discussed according to the molar ratios of precursors and the bond theory. The resulting centimeter-sized MAPbBr 3 crystals exhibit high resistivity (5.6 × 10 8 Ω•cm) at room temperature. The mobility−lifetime (μτ) products are measured under 241 Am (5.48 MeV) α particles irradiation, with the values of 2.2 × 10 −4 and 4.2 × 10 −4 cm 2 /V for electrons and holes, respectively. Simultaneously, the electrons and holes mobility are estimated to be 24.6 and 59.7 cm 2 /(V•s), respectively, using the α-source-induced transient waveforms.

Compared with the widely reported MAPbBr 3 single crystals, formamidinium-based (FA-based) hybrid perovskites FAPbBr 3 (FPB) with superior chemical and structure stability are expected to be more efficient and perform as more reliable radiation detectors at room temperature. Here, we employ an improved inverse temperature crystallization method to grow FPB bulk single crystals, where issues associated with the retrograde solubility behavior are resolved. A crystal growth phase diagram has been proposed, and accordingly, growth parameters are optimized to avoid the formation of NH 4 Pb 2 Br 5 secondary phase. The resulting FPB crystals exhibit a high resistivity of 2.8 × 10 9 Ω•cm and high electron and hole mobility−lifetime products (μτ) of 8.0 × 10 −4 and 1.1 × 10 −3 cm 2 •V −1 , respectively. Simultaneously, the electron and hole mobilities (μ) are evaluated to be 22.2 and 66.1 cm 2 •V −1 •s −1 , respectively, based on the time-of-flight technique. Furthermore, a Au/FPB SC/Au detector is constructed that demonstrates a resolvable gamma peak from 59.5 keV 241 Am γ-rays at room temperature for the first time. An energy resolution of 40.1% is obtained at 30 V by collecting the hole signals. These results demonstrate the great potential of FAPbBr 3 as a hybrid material for γ-ray spectroscopy and imaging.

The ferroic domain, in metal halide perovskites (MHPs) at a low symmetry phase, was reported to affect optoelectronic properties. Building the relationship between ferroic domains and optoelectronic properties of MHPs will be a non-trivial task for understanding the charge transport mechanism. Here, high-quality CsPbBr3 single-crystal films (SCFs) were successfully grown by a cast-capping method. Through the phase transition process by heating and cooling the sample, dense domains in CsPbBr3 SCFs were formed and observed by an in situ polarized optical microscope. These domains were identified as 90° rotation twins by electron backscattered diffraction and transmission electron microscopy. Interestingly, the photocurrent response was dramatically enhanced after introducing ferroelastic domains. The highest responsivity, external quantum efficiency, and detectivity are 380 mA/W, 130%, and 12.9 × 1010 Jones, respectively, which are surprisingly 25.03, 25, and 7.8 times higher than those of the as-grown CsPbBr3 SCF, respectively, which may be attributed to the function of the domain wall of separating electrons and holes.