Inorganic Halide Perovskitoid TlPbI₃ for Ionizing Radiation Detection

Abstract

Room temperature semiconductor detector (RTSD) materials for γ‐ray and X‐ray radiation are in great demand for the nonproliferation of nuclear materials as well as for biomedical imaging applications. Halide perovskites have attracted great attention as emerging and promising RTSD materials. In this contribution, the material synthesis, purification, crystal growth, crystal structure, photoluminescence properties, ionizing radiation detection performance, and electronic structure of the inorganic halide perovskitoid compound TlPbI3 are reported on. This compound crystallizes in the ABX3 non‐perovskite crystal structure with a high density of d = 6.488 g·cm–3, has a wide bandgap of 2.25 eV, and melts congruently at a low temperature of 360 °C without phase transitions, which allows for facile growth of high quality crystals with few thermally‐activated defects. High‐quality TlPbI3 single crystals of centimeter‐size are grown using the vertical Bridgman method using purified raw materials. A high electrical resistivity of ≈1012 Ω·cm is readily obtainable, and detectors made of TlPbI3 single crystals are highly photoresponsive to Ag Kα X‐rays (22.4 keV), and detects 122 keV γ‐rays from 57Co radiation source. The electron mobility‐lifetime product µeτe was estimated at 1.8 × 10–5 cm2·V–1. A high relative static dielectric constant of 35.0 indicates strong capability in screening carrier scattering and charged defects in TlPbI3.

Structural dimension modulation in a new oxysulfide system of Ae2Sb2O2S3 (Ae = Ca and Ba)

“…The above-band-gap PL emissions of the two compounds should originate from the processes involving defect levels below the valence band maximum or above the conduction band minimum. Such above-band-gap PL emissions were also observed in other compounds, such as CH 3 NH 3 PbI 3 , 39 CsPbCl 3 , CsPbBr 3 , 40 TlPbI 3 , 41 GaAs 1− x N x 42 and GaAs 1− x P x . 43 The similar PL emission behaviors indicate similar types of defects in the two closely-related compounds.…”

Simultaneous Manipulation of Interfacial and Defects Polarization toward Zn/Co Phase and Ion Hybrids for Electromagnetic Wave Absorption

“…It can be observed in Figure 2g that, HMs obtained with no TEA showed absolutely higher ε′ and ε″ values, which can be attributed to the abundant "polarization centers" caused by defects and heteroatoms. [38] Herein, the X-ray photoelectron spectroscopy (XPS) spectra of HMs obtained by no TEA confirmed that the 800 °C HMs had more defects than 600 °C HMs (Figures S7 and S8, Supporting Information), especially the Zn 2p peaks of 800 °C HMs were widened. [39] Nevertheless, the conductivity of HMs obtained with 8 mmol TEA was a little bit higher than that with 4 mmol TEA, which may be attributed to the pinning effect.…”

Highly efficient and stable perovskite solar cells enabled by low-dimensional perovskitoids

“…However, the results from using this approach are not completely satisfactory due to the tendency of forming multicomponent structures in the quasi-2D phase and creating lattice strain during the formation of low-dimensional (LD) structures. Recently, perovskitoid has been proposed to describe the structures where the PbI 6 octahedra are linked by edge and face sharing or combinations of corner, edge, and face sharing (26)(27)(28)(29)(30)(31)(32). Perovskitoids have the potential to effectively modify 3D perovskite due to its diverse PbI 6 connection styles and high stability.…”