Enhanced Stability of Melt-Processable Organic-Inorganic Hybrid Manganese Halides for X-Ray Imaging.

Mn-based metal halides scintillators with high photoluminescence quantum yield (PLQY) have recently emerged as promising large-size candidates for X-ray imaging but still remains as difficult challenge in stability and high processing temperatures. Here, three manganese halides are designed by introducing branched chains into organic cations and extending the carbon chains, namely (i-PrTPP)MnBr, (i-BuTPP)MnBr and (i-AmTPP)MnBr, successfully lowered the melting point of manganese halides to 120.2 °C. Three materials show striking light yields of 59 000, 40 000, and 52 000 photons MeV, respectively. The lowest detection limits are 42.30, 50.92, and 45.71 nGy s, respectively. Meanwhile, compared to their counterparts with linear carbon chains, the introduction of branched chains has significantly enhanced the stability of the scintillators in the glass state. A transparent glass has been prepared using a melt-quenching method, which exhibited 80% transmittance at 400-700 nm. The glass is utilized for X-ray imaging, achieving a high spatial resolution up to 46.6 lp mm. This result provides a new approach to enhancing the performance of such scintillator materials.