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Cd2+ cation doped CsPbCl3 single crystals were synthesized, and their luminescent properties were investigated under excitation with synchrotron radiation quanta with energy greater than Eg and at a sample temperature of 12 K. Pure single crystals exhibit a narrow band of exciton emission at 416.7 nm. Doping the single crystals leads to a high-energy shift of the excitonic luminescence, the appearance of new luminescent bands, the broadening of the luminescent bands, an increase in the decay time constants, and a significant enhancement of the luminescence intensity. The observed changes in luminescent parameters upon doping are discussed in terms of the crystal structure ordering, a decrease in the number of defects responsible for capturing charge carriers at the stage of electronic excitation thermalization, and a decrease in defects that quench excitonic luminescence. Doped single crystals with decay times of the order of 0.4 ns and intensities that significantly exceed the intensity of pure single crystals can be promising scintillation materials for positron emission tomography in the time-of-flight mode. [ABSTRACT FROM AUTHOR]

Conventional photonic crystals with a single period are capable of enhancing the light output of scintillators based on the partial elimination of internal total reflection. However, the enhancement often comes along with a strong wavelength dependence, leading to a severe spectrum distortion. Here, the nanostructures for wavelength-independent light extraction enhancement, namely, multi-size spherical nanostructures, are designed and fabricated. The nanostructure can efficiently outcouple the scintillation light and at the same time significantly weaken the wavelength dependence. The light output of the scintillators with the nanostructures obtains noticeable enhancement with a ratio of 1.7, having weak wavelength dependence, which is in contrast to the enhancement by single-periodic photonic crystals. In addition to the applications on the scintillators, we anticipate that these wavelength-independent light output enhancement schemes could be expanded to other important fields, such as white light-emitting diodes and display devices. [ABSTRACT FROM AUTHOR]

Low output power has long been the bottleneck of micro-radioisotope batteries as power supplies for the wireless sensor network, implantable medical equipment, and outer space exploration. Recently, x-ray radioluminescent batteries demonstrated the great potential to break the deadlock. In this work, we fabricated an x-ray radioluminescent battery with near milliwatt output power and demonstrated various potential applications. A 100% improvement on the conversion efficiency of 2.46% and the highest output power of 136.1 μW/cm2 were achieved when adopting a thallium doped cesium iodide (CsI:Tl) single-crystal scintillator in the battery. Subsequently, a 2 × 2 battery array was fabricated with a maximum output power of 466.9 μW and was used to power devices including micro-LEDs and a wireless sensor system with temperature monitoring. This demo system shows the feasibility of x-ray radioluminescent batteries as a long-lifetime micropower. The tremendous progress will draw broad attention on micro-nuclear batteries and inspire further exploration on the applications in the field of medical devices, space explorations, and Internet of Things. [ABSTRACT FROM AUTHOR]

β-Ga2O3 is a potential fast semiconductor scintillator with no significant self-absorption and excellent stability. However, the relatively low light yield of β-Ga2O3 at room temperature limits its practical application. In order to improve its scintillation performance, Al3+ doped β-Ga2O3 single crystals are investigated. By doping 5%Al3+ (atomic concentration), the light yield of β-Ga2O3 is increased from 4394 to 6816 ph/MeV. The increased light yield may be attributed to the decreased free electron concentration and inhibition of Auger nonradiative recombination. The thermal quenching effect can also be moderated by the increase in the thermal activation energy induced by Al3+ doping. The results indicate that Al3+ doping is an effective method to increase the light yield of β-Ga2O3. [ABSTRACT FROM AUTHOR]

Low energy conversion efficiency and low output power are the major limiting factors of isotope batteries as miniature power supplies for the broad applications, such as micro-electromechanical systems and aerospace electronics. In this work, highly efficient x-ray radioluminescent batteries are demonstrated based on single-crystal scintillators and spectra-matched photovoltaic batteries. X-ray sources are chosen to reduce the backscattering loss, and cerium doped Gd3Al2Ga3O12 (GAGG:Ce) single-crystal scintillators are adopted to improve the radioluminescence efficiency and light coupling efficiency, for their high x-ray absorption ability and high light-yield. The bandgap of photovoltaic battery is also optimized to match the luminescence spectrum of GAGG:Ce to maximize the photovoltaic efficiency. An optimal radioluminescent battery is achieved with an output power of 13.4 μW/cm2 and a conversion efficiency of 1.28%, which is a 10.7-times improvement in the previous best reports (0.12%). This exciting progress indicates the promising potential of radioluminescent batteries in broad applications and will inspire the further exploration for the research community of radioisotope batteries. [ABSTRACT FROM AUTHOR]