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Upconversion luminescence plays a crucial role in various technological applications, and among the various valence states of lanthanide elements, Ln 3+ has the highest stability. The 4f orbitals of these elements are in a fully empty, semifull, or full state. This special 4f electron configuration allows them to exhibit rich discrete energy levels. However, the 4f-4f transition of Ln 3+ rare earth ions itself is prohibited, resulting in a lower luminescence efficiency. This limitation greatly hinders the practical application of upconversion luminescence. In this study, we report nanostructured luminescence-enhanced substrate platforms with both semiconductive local surface plasmons and spatially confined domain effects on a single defect semiconductor substrate. By coupling NaYF 4 :Yb-Er nanoparticle emitters to the surface of Ti 3 O 5 NC-arrays plasmonic nanostructures, an ultrabright luminescence with a 32-fold increase in green emission and a 40-fold increase in red emission was achieved. Furthermore, the fluorescence resonance energy transfer characteristics observed in the R6G/NaYF 4 /Ti 3 O 5 NC-array composite film enable accurate detection of fluorescent molecules. The results provide an innovative and intelligent approach to enhance the upconversion luminescence intensity of rare-doped nanoparticles and develop highly sensitive molecular detection systems based on the above luminescence enhancement.

Halide perovskite materials have been used in the field of lithium-ion batteries because of their excellent ion migration characteristics and defect tolerance. However, the current lead-based perovskites used for lithium-ion batteries are highly toxic, which may hinder the pace of further commercialization. Therefore, it is still necessary to develop a new type of stable and pollution-free perovskite anode material. Herein, we for the first time use a high-concentration lithium-ion doped rare-earth-based double perovskite Cs 2 NaErCl 6 :Li + as the negative electrode material for a lithium-ion battery. Thanks to its excellent structure stability, the assembled battery also has high cycle stability, with a specific capacity of 120 mAh g -1 at 300 mA g -1 after 500 cycles with a Coulomb efficiency of nearly 100%. The introduction of a rare earth element in a lead-free double perovskite paves a new way for the development of novel promising anode materials in the field of lithium storage applications.

Perovskite materials, as a multifunctional material, have been widely applied in the field of electrochemistry due to its ion migration properties. Although the lead based halide perovskite has been applied in the anode of the lithium battery, it is necessary to develop new lead-free perovskite anode materials because of its the instability and environmental unfriendliness. Herein, we develop a facile grinding method to prepare ultrahigh Li + concentration doping Cs 2 NaBiCl 6 powders, which are used as the anode material of the lithium battery. The assembled battery possesses a stable specific capacity of about 300 mA h g -1 with over 99% Coulombic efficiency. Owing to their particular crystal structure with high adjustability, the double perovskite materials have promising potentials in lithium storage applications.

Latent fingerprints (LFPs) are important evidence in crime scenes and forensic investigations, but they are invisible to the naked eye. In this work, a novel fluorescent probe was developed by integrating a narrow-band-emitting green afterglow phosphor, SrGa 12 O 19 :Mn 2+ (SGO:Mn), and ethyl cellulose (EC) for the efficient visualization of LFPs. The hydrophobic interactions between the powder and lipid-rich LFPs made the ridge structures more defined and easily identifiable. The background fluorescence of the substrates was completely avoided because of the time-gated fluorescence of the afterglow phosphor. All the three levels of LFP degrees were clearly imaged due to the high sensitivity. Moreover, the SGO:Mn-EC powder was highly stable in neutral, acidic, and alkaline environments. In addition, 60 day-aged LFPs were successfully visualized by the powder. All performances showed that this strategy for LFP recognition has merits such as low cost, non-destructive nature, reliability, superior universality, and legible details. Together, these results show the great application prospects of this powder in forensic identification and criminal investigation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Fetal weight is an important factor to determine the delivery mode of pregnant women. The change of fetal weight is significant, according to regular health monitoring of pregnant women. Conventional methods of fetal weight estimation, namely those based on B-ultrasound, are very complicated and the costs are high. In this paper, we propose a new method based on body composition. An abdominal four-segment impedance model is first established upon pregnant women, as well as the method of calculation. A body composition based method is then given to estimate the fetal weight, with the solution given explicitly. Analyses of clinical data reveal the smallness of the error between the estimated value and the actual value. The error between B-ultrasound and the present method is less than 15%.

All-inorganic metal halide perovskites of the formulation ABX 3 (where A is Cs + , B is commonly Pb 2+ , and X is a halide, X = Cl, Br, I) have been studied intensively for their unique properties. Most of the current studies focus on halogen exchange to modify the luminescence band gap. Herein we demonstrate a new avenue for changing the band gap of halide perovskites by designing mixed-monovalent cation perovskite-based colloidal quantum dot materials. We have synthesized monodisperse colloidal quantum dots of all-inorganic rubidium-cesium lead halide perovskites (APbBr 3 , A = mixed monovalent cation systems Rb/Cs) using inexpensive commercial precursors. Through the compositional modulation, the band gap and emission spectra are readily tunable over the visible spectral range of 474-532 nm. The photoluminescence (PL) of Rb x Cs 1-x PbBr 3 nanocrystals is characterized with excellent (NTCS color standard) wide color gamut coverage, which is similar to the cesium lead halide perovskites (CsPbX 3 , X = mixed halide systems Cl/Br), and narrow emission line-widths of 27-34 nm. Furthermore, simulated lattice models and band structures are used to explain the band gap variations.