Cs3Bi2I9 single crystals with significant anisotropies show a capability of detecting 241Am@5.49 MeV α particles ((FWHM) of ∼32%).

The metal halide perovskite CsPbBr 3 bulk crystals present electrical and optical performance discrepancy since the grown-in defects. Here, we first report the well-defined secondary phase (SP) particles of CsPb 2 Br 5 with polyhedral morphology in CsPbBr 3 crystals grown by the vertical Bridgman method. The resulting polyhedral morphology of CsPb 2 Br 5 particles associated with the trapping of PbBr 2 -rich droplets have been discussed on the basis of the "matrix-controlled" growth. Two morphological evolution paths are proposed, which result in a regular cube SP particle comprised by {100} facets for the final equilibrium. Furthermore, the wafer with superior optical transmittance exhibits a higher photoelectric response on−off ratio (∼2000) in contrast to ∼80 for the wafer with high density SP particles. The corresponding hole mobility (μ h ) is calculated with the values 289.99 and 26.91 cm −2 • V −1 •s −1 , respectively. The variation of μ h is attributed to the carrier transport trajectory affected by SP induced trapping defects and the weak combination.

A CsPbBr 3 single crystal exhibits great potentials in X-ray/gamma-ray spectroscopy and imaging. Here, an inverse temperature crystallization (ITC) method with modified precursor composition is proposed to prepare CsPbBr 3 single crystals. The introduction of adduct PbBr 2 •2DMSO, synthesized by the antisolvent vaporassisted crystallization method, in the precursor solution gives rise to superior crystallization with a lower impurity concentration and higher resistivity of 6.37 × 10 9 Ω•cm, as well as a higher hole mobility (50.7 cm 2 •V −1 •s −1 ). Furthermore, a low dark current of 2.3 nA is obtained at a bias of −100 V based on an as-grown crystal with a thickness of 1 mm, according to the asymmetric Au/CsPbBr 3 /Sn structure. The resulting asymmetric planar detectors achieve the high peak-to-valley ratio pulse height spectra with an energy resolution of 7.66%, illuminated by an uncollimated 241 Am@5.5 MeV α particle. Simultaneously, an energy resolution of 13.5% is realized when irradiated by a 59.5 keV 241 Am γ-ray source at room temperature. The thermally stimulated current (TSC) spectra indicate that the density of deep energy-level trap is significantly reduced in the CsPbBr 3 crystals grown by PbBr 2 •2DMSO-modified precursor solution, which is consistent with the high performance in radiation detection.

The understanding and tailoring of crystalline defects have been a cornerstone of established semiconductors technological deployment. Here, we report the secondary phase (SP) defects of CsPb2Br5 in CsPbBr3 crystals grown...