Lanthanide(III)‐Cu₄I₄ Organic Framework Scintillators Sensitized by Cluster‐Based Antenna for High‐Resolution X‐ray Imaging

Abstract

Scintillator‐based X‐ray imaging has attracted great attention from industrial quality inspection and security to medical diagnostics. Herein, a series of lanthanide(III)‐Cu4I4 heterometallic organic frameworks (Ln‐Cu4I4 MOFs)‐based X‐ray scintillators are developed by rationally assembling X‐ray absorption centers ([Cu4I4] clusters) and luminescent chromophores (Ln(III) ions) in a specific manner. Under X‐ray irradiation, the heavy inorganic units ([Cu4I4] clusters) absorb the X‐ray energy to populate triplet excitons via halide‐to‐ligand charge transfer (XLCT) combined with the metal‐to‐ligand charge‐transfer (MLCT) state (defined as the X/MLCT state), and then the 3X/MLCT excited state sensitizes Tb3+ for intense X‐ray‐excited luminescence via excitation energy transfer. The obtained Tb‐Cu4I4 MOF scintillators exhibit high resistance to humidity and radiation, excellent linear response to X‐ray dose rate, and high X‐ray relative light yield of 29 379 ± 3000 photons MeV−1. The relative light yield of Tb‐Cu4I4 MOFs is ≈3 times higher than that of the control Tb(III) complex. X‐ray imaging tests show that the Tb‐Cu4I4 MOFs‐based flexible scintillator film exhibits a high spatial resolution of 12.6 lp mm−1. These findings not only provide a promising design strategy to develop lanthanide‐MOF‐based scintillators with excellent scintillation performance, but also exhibit high‐resolution X‐ray imaging for biological specimens and electronic chips.

Modulating Nonluminous 0D (NH4)2SnCl6 Perovskites by Metal Ion Doping

“…Organic–inorganic hybrid metal halides possess unique advantages and have attracted wide attention in optical applications such as white light-emitting diodes (WLEDs), solar cells, solar concentrators, and scintillators. − In addition, the flexible combination of organic cations and center metal ions allows great variations in their structure and performance. Organic cations or central metal atoms generally exhibit a hybrid metal halide photoluminescence (PL) behavior. ,, Among many organic–inorganic hybrid halides, lead-based perovskites are of more interest due to their high electronic dimensionality, low cost, easy processing, and high photoluminescence quantum yield (PLQY). − Moreover, 0D perovskites possess typical self-trapping excitons (STEs) due to the violent interaction between excitons and phonons, leading to a broad emission and a large Stokes shift, which is more conducive to being applied in WLEDs. , However, the toxicity of traditional lead halide perovskites has greatly limited their practical applications.…”

Chiral hybrid manganese(ii) halide clusters with circularly polarized luminescence for X-ray imaging

“…The modulation transfer function (MTF) extracted from the X-ray image of the slanted edge is also used to confirm the spatial resolution of the R -2 screen. 25 In Fig. S7 in the ESI,† the X-ray images of the slanted edge and the thin lead slice with a sharp edge are shown.…”

“…Due to the advantages of eco-friendliness, low cost and high luminescence quantum efficiency, manganese( ii ) halides can be used for promising and efficient luminescent materials. 23–26 Their luminescence mechanism comes from the d orbital electron transition in the crystal field. 27–29 At present, manganese-based hybrid halides are widely used in light-emitting diodes, solar cells, photoelectric detection and other fields.…”

Red‐Emitting Organic–Inorganic Hybrid Manganese(II) Halides for X‐Ray Imaging

“…The conversion efficiency of steady-state X-ray to visible light is defined as the ratio of emitted photon counts to the total absorbed X-ray energy. [33,48] To accurately evaluate the steadystate scintillation yield of the samples, it is a must to consider the X-ray attenuation efficiency factor. Figure S4 (Supporting Information) shows the curve of the X-ray attenuation efficiency of (Gua) 2 MnCl 4 as a function of sample thickness.…”