Solution‐Processed Lead‐Free Perovskite Nanocrystal Scintillators for High‐Resolution X‐Ray CT Imaging

Abstract

The physical properties of scintillators determine X‐ray detection performance directly, which plays a vital role in computed tomography (CT) imaging for medical radiography and security checks. Recently, lead halide perovskite materials have shown higher photoluminescence quantum yield (PLQY) than conventional X‐ray scintillators, but there are still some limitations, including instability and the use of heavy metal lead. In this study, a low‐temperature solution method is used to prepare 0D lead‐free Cs3Cu2I5 perovskite nanocrystals (NCs), and a corresponding optical fiber panel with Cs3Cu2I5 NCs is fabricated for high‐resolution X‐ray CT imaging. The Cs3Cu2I5 NCs exhibit a high PLQY of 59% and outstanding stability for more than three months. Importantly, the Cs3Cu2I5 NCs show a high radioluminescence (RL) light yield, that is four times higher than that of CsPbBr3 NCs (80 kV, 70 µA). In addition, an X‐ray detector based on a Cs3Cu2I5 NC scintillator is designed. Using this system, a clear projection image of a chip is obtained, and a 3D CT image of a snail is reconstructed. Therefore, the use of lead‐free perovskite nanocrystal scintillators is a promising technique for commercial X‐ray detection.

Pressure‐assisted cooling to grow ultra‐stable Cs3Cu2l5 and CsCu2l3 single crystals for solid‐state lighting and visible light communication

“…However, for classic lead halide perovskites, their toxicity of lead elements have been reported to impede their development in commercialization 6–10 . Consequently, lead‐free halide perovskites are desirable in promoting the development of optoelectronic devices, including solar cells, 11 white light‐emitting diodes (WLEDs), 12–14 photodetectors 15–17 and X‐ray scintillators 18–20 . Among all lead‐free halide perovskites, inorganic copper halide perovskites have been explored as excellent candidates for highly efficient WLEDs 21 and detectors 22 .…”

Flexible, High Scintillation Yield Cu3Cu2I5 Film Made of Ball‐Milled Powder for High Spatial Resolution X‐Ray Imaging

“…[ 4,5,10,11 ] Quantum confinement effect shows a decisive impact on the electronic structure as well as the optoelectronic properties, which has been guide the development of new scintillation materials with less overlap between the absorption and emission spectrum. [ 12–19 ] Materials with molecular level low electronic dimensional structure like quantum well (2D), quantum wire (1D) and isolated cluster (0D) have been developed and investigated, which shown promising scintillation ability. In these materials, 0D and 1D coper hailed materials like Rb 2 CuBr 3 , [ 13 ] Rb 2 CuCl 3 , [ 18 ] CsCu 2 I 3 , [ 19 ] Cs 3 Cu 2 I 5 , [ 14,15,20 ] Cs 5 Cu 3 Cl 6 I 2 [ 21 ] demonstrate high photoluminescence quantum yield (PLQY), large light yield and large Stokes shifts, which can be attributed the self‐trapped exciton (STE) induced light emission.…”

All-inorganic perovskite nanocrystals: next-generation scintillation materials for high-resolution X-ray imaging

“…75 Small stokes-shift and strong self-absorption are reported to be the main causes for the limited light yield of Pb-halide perovskite thin-films/nanocrystals. 76,77 And from the perspectives of environmental protection and sustainable development, the practical applications of Pb-halide perovskites will be severely restricted due to the toxicity of Pb and the material instability. 78 Thus, developing stable Pb-free perovskites with high PLQY becomes a new research hotspot.…”

“…78 Thus, developing stable Pb- free perovskites with high PLQY becomes a new research hotspot. 27,77 The summary of the key parameters for various scintillators from conventional materials to recent Pb-free perovskites in X-ray imaging has been indicated in Table 1.…”