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We disclose the intrinsic semiconducting properties of one of the largest mixed‐valent uranium clusters, [H3O+][UV(UVIO2)8(μ3‐O)6(PhCOO)2(Py(CH2O)2)4(DMF)4] (Ph=phenyl, Py=pyridyl, DMF=N,N‐dimethylformamide) (1). Single‐crystal X‐ray crystallography demonstrates that UV center is stabilized within a tetraoxo core surrounded by eight uranyl(VI) pentagonal bipyramidal centers. The oxidation states of uranium are substantiated by spectroscopic data and magnetic susceptibility measurement. Electronic spectroscopy and theory corroborate that UV species serve as electron donors and thus facilitate 1 being a n‐type semiconductor. With the largest effective atomic number among all reported radiation‐detection semiconductor materials, charge transport properties and photoconductivity were investigated under X‐ray excitation for 1: a large on‐off ratio of 500 and considerable charge mobility lifetime product of 2.3×10−4 cm2 V−1, as well as a high detection sensitivity of 23.4 μC Gyair−1 cm−2. [ABSTRACT FROM AUTHOR]

Scintillators are a unique class of luminescent materials with specific applications towards radiation detection. The emitters within state‐of‐the‐art scintillators are mostly limited to bismuth, cerium, europium, thallium, lead, tungsten, etc. A shared feature of these elements is the relatively high atomic number, which is responsible for high radiation stopping power and radiation‐induced luminescence. Searching for new scintillating materials is an essential target aiming at specific applications. In this Concept article, we will discuss our recent works on the topic of "uranyl‐bearing scintillators". As a virgin territory in this field, uranyl‐bearing scintillators show intrinsic merits for designing new materials with X‐ray detection capability, that is, the large photoelectric cross‐section, high X‐ray attenuation efficiency, and high crystal density. In addition, we also present challenges in the further development of the uranyl‐bearing scintillators. [ABSTRACT FROM AUTHOR]

Keywords: luminescence; radiation detection; scintillators; uranium As a new area in this field, uranyl-bearing scintillators show intrinsic merits for designing new materials with X-ray detection capability, that is, a large photoelectric cross-section, high X-ray attenuation efficiency, and high crystal density. Luminescence, radiation detection, scintillators, uranium. [Extracted from the article]