X-ray-induced photodynamic therapy utilizes penetrating X-rays to activate reactive oxygen species in deep tissues for cancer treatment, which combines the advantages of photodynamic therapy and radiotherapy. Conventional therapy usually requires heavy-metal-containing inorganic scintillators and organic photosensitizers to generate singlet oxygen. Here, we report a more convenient strategy for X-ray-induced photodynamic therapy based on a class of organic phosphorescence nanoscintillators, that act in a dual capacity as scintillators and photosensitizers. The resulting low dose of 0.4 Gy and negligible adverse effects demonstrate the great potential for the treatment of deep tumours. These findings provide an optional route that leverages the optical properties of purely organic scintillators for deep-tissue photodynamic therapy. Furthermore, these organic nanoscintillators offer an opportunity to expand applications in the fields of biomaterials and nanobiotechnology.

Intermolecular interactions, including attractive and repulsive interactions, play a vital role in manipulating functionalization of the materials from micro to macro dimensions. Despite great success in generation of ultralong organic phosphorescence (UOP) by suppressing non-radiative transitions through attractive interactions recently, there is still no consideration of repulsive interactions on UOP. Herein, we proposed a feasible approach by introducing carboxyl groups into organic phosphors, enabling formation of the intense repulsive interactions between the isolated molecules and the matrix in rigid environment. Our experimental results show a phosphor with a record lifetime and quantum efficiency up to 3.16 s and 50.0% simultaneously in film under ambient conditions. Considering the multiple functions of the flexible films, the potential applications in anti-counterfeiting, afterglow display and visual frequency indicators were demonstrated. This finding not only outlines a fundamental principle to achieve bright organic phosphorescence in film, but also expands the potential applications of UOP materials.

Room temperature phosphorescence (RTP) in metal‐free organic materials has attracted considerable attention due to its rich excited state properties, high quantum efficiency, long luminescence lifetimes, etc., showing great potential in organic optoelectronic devices, bioimaging, information anti‐counterfeiting, and so forth. The crystals have excellent rigidity and clear molecular packing patterns, which can effectively avoid non‐radiative transitions of excitons for phosphorescence enhancement. In the early stages, researchers paid great attention to the regulation of RTP performance in crystalline states. However, due to the complex preparation and poor processability of crystals, amorphous materials with RTP features have become a new research topic recently. This perspective aims to summarize the recent advances of RTP materials from crystalline to amorphous states, and analyze their molecular design strategies and luminescence mechanisms in detail. Finally, we prospect the future research directions of amorphous RTP materials. This perspective will provide a guideline for the future study of advanced RTP materials.

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Purely organic room‐temperature phosphorescence (RTP) materials have attracted increasing attention due to their unique photophysical properties and widespread optoelectrical applications, but the pursuit of high quantum yield is still a continual struggle for RTP emission under ambient conditions. Here, a series of novel RTP molecules (26CIM, 246CIM, 24CIM, and 25CIM) are developed on the basis of indole luminophore, in which a carbonyl group bridges indole and chloro‐substituted phenyl group. The structural isomerism is systematically regulated toward enhancing the intramolecular‐space heavy‐atom effect, thus promoting the spin–orbit coupling and intersystem crossing for high RTP efficiency. While rationally modulating the intramolecular‐space heavy‐atom effect, the phosphorescence efficiency is dramatically increased by 16‐fold from 2.9% (24CIM) to 48.9% (26CIM). Basically, the fully occupied chlorine atoms at the positions 2 and 6 can effectively favor the stronger intramolecular H…Cl effect, and the tight lock coupling with anti‐parallel stacking in 26CIM further boosts RTP emission synergistically. The experimental findings along with deeper theoretical insights elucidate the structure–performance relationship clearly, and further suggest a general strategy for rationally constructing high‐efficiency RTP materials.

Pb(Zr0.52Ti0.48)O3/polycarbonate (PZT/PC) composite films with different concentration of PZT ferroelectric nanocrystals are prepared. The polarization and dielectric relaxation behavior of PZT ferroelectric nanocrystals are characterized using in situ transmittance and X-ray diffraction (XRD) measurements for the first time. It’s found that 10% PZT/PC composite film has the largest orientation change and negligible dielectric relaxation after poling (the φ value of 13.8% is almost constant with time even for 168 h). Based on the XRD results, we consider that the preferential orientation of PZT nanocrystals to align in PC matrix after poling is [001] direction.

Phosphorescent cocrystal is one of the emerging room-temperature phosphorescence (RTP) materials. However, it remains a great challenge to understand the relationship between the phosphorescent properties and molecular aggregation. Herein, we prepared a series of organic cocrystals with RTP features composed of different alkyl chain lengths. It is worth noting that the phosphorescent lifetime varied by the different lengths of alkyl chains. For melamine−succinic acid cocrystal, the phosphorescence lifetime can reach up to 512 ms. From the single-crystal analysis, the longer lifetime was mainly attributed to the shorter distance of molecular stacking between phosphorescent chromophores resulting in smaller free volume. This study not only provides a simple method to prepare RTP materials but also explores the relationship between phosphorescent properties and molecular stacking in organic phosphorescent cocrystals.

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