Influence of Isomerism on Radioluminescence of Purely Organic Phosphorescence Scintillators

Abstract

There are few reports about purely organic phosphorescence scintillators, and the relationship between molecular structures and radioluminescence in organic scintillators is still unclear. Here, we presented isomerism strategy to study the effect of molecular structures on radioluminescence. The isomers can achieve phosphorescence efficiency of up to 22.8 % by ultraviolet irradiation. Under X-ray irradiation, both m-BA and p-BA show excellent radioluminescence, while o-BA has almost no radioluminescence. Through experimental and theoretical investigation, we found that radioluminescence was not only affected by non-radiation in emissive process, but also highly depended on the material conductivity caused by the different molecular packing. This study not only allows us to clearly understand the relationship between the molecular structures and radioluminescence, but also provides a guidance to rationally design new organic scintillators.Scintillators are a type of luminescence materials that can convert high energy photons or particles to visible photons, [1] which receive extensive attention in various fields, such as medical imaging [2] and irradiation detecting. [3] To date, scintillators are mainly divided into two categories, inorganic and organic scintillators. Compared with inorganic scintilla-

Heavy-atom engineering of thermally activated delayed fluorophores for high-performance X-ray imaging scintillators

“…More importantly, the X-ray imaging screens created using TADF-Br chromophore exhibited a relative light yield of approximately 20,000 photons/MeV, which is 5 times higher than that of the best TADF scintillator reported recently (the highest relative light yield among reported TADF scintillators is 3700 photons/MeV 15 according to the calculation method provided in this article). 15,19,32,33 In addition, the detection limit of 64.5 nGy s -1 obtained for the TADF-Br film is several times lower than the standard dosage for X-ray diagnostics (5.5 μGy s -1 ) 1 . Moreover, a high X-ray imaging resolution of 18.3 lp mm -1 can be achieved, exceeding all the reported organic and most conventional inorganic scintillators.…”

Tunable Second‐Level Room‐Temperature Phosphorescence of Solid Supramolecules between Acrylamide–Phenylpyridium Copolymers and Cucurbit[7]uril

“…[6] However, acquirement of purely organic phosphorescence with a long lifetime faces a great challenge because of the inherently weak spinorbital coupling (SOC) or fast intersystem crossing (ISC) process and multiple deactivation pathways of organic molecules, all of which will shorten the phosphorescence lifetime (microsecond-or millisecond-level), and even cause the lack of phosphorescence. [7] To achieve long-lived and high-performance purely organic phosphorescence, lots of effort have gone into the design and synthesis, including crystallization, [8][9][10][11] embedding chromophores into the matrix, [12][13][14] polymerization, [15][16][17] deuterium substitution, [18] supramolecular host-guest interaction, [2e, 19, 20] and so on, [21,22] most of which are mainly based on the principle of minimizing nonradiative relaxation and enhancing the ISC process of excitons from the lowest singlet excited state (S 1 ) to the triplet manifold (T n ). Although there are numerous outstanding works, second-level phosphorescence emission is still rare.…”

Role of halogen effects and cyclic imide groups in constructing red and near-infrared room temperature phosphorescence molecules: theoretical perspective and molecular design

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