CsPbBr3 Quantum Dot Films with High Luminescence Efficiency and Irradiation Stability for Radioluminescent Nuclear Battery Application

Fe2O3/MoO3@NG Heterostructure Enables High Pseudocapacitance and Fast Electrochemical Reaction Kinetics for Lithium-Ion Batteries

Transition metal oxides (TMOs) hold great potential for lithium-ion batteries (LIBs) on account of the high theoretical capacity. Unfortunately, the unfavorable volume expansion and low intrinsic electronic conductivity of TMOs lead to irreversible structural degradation, disordered particle agglomeration, and sluggish electrochemical reaction kinetics, which result in perishing rate capability and long-term stability. This work reports an Fe₂O₃/MoO₃@NG heterostructure composite for LIBs through the uniform growth of Fe₂O₃/MoO₃ heterostructure quantum dots (HQDs) on the N-doped rGO (NG). Due to the synergistic effects of the "couple tree"-type heterostructures constructed by Fe₂O₃ and MoO₃ with NG, Fe₂O₃/MoO₃@NG delivers a prominent rate performance (322 mA h g^-1 at 20 A g^-1, 5.0 times higher than that of Fe₂O₃@NG) and long-term cycle stability (433.5 mA h g^-1 after 1700 cycles at 10 A g^-1). Theoretical calculations elucidate that the strong covalent Fe-O-Mo, Mo-N, and Fe-N bonds weaken the diffusion energy barrier and promote the Li⁺-ion reaction to Fe₂O₃/MoO₃@NG, thereby facilitating the structural stability, pseudocapacitance contribution, and electrochemical reaction kinetics. This work may provide a feasible strategy to promote the practical application of TMO-based LIBs.

Highly stable CsPbBr3 perovskite quantum dot-doped tellurite glass nanocomposite scintillator

All-inorganic cesium lead halide perovskite quantum dots (PQDs) appear to be promising scintillators for radiation detection; however, they are suffering from poor stabilities against light, heat, and moisture. Here a strategy of using AgCl as the nucleating agent is developed to facilitate growth of CsPbBr₃ PQDs in chemically inert tellurite glasses via controlled crystallization. The PQDs are uniformly dispersed and well protected in the dense glass matrix without aggregation. The nanocomposites thus obtained are featured by excellent optical transparency owing to the unique character of tellurite glass having a refractive index comparable to that of the CsPbBr₃ crystal. The X-ray excited radioluminescence properties are comprehensively studied. The results show that CsPbBr₃ PQD-doped tellurite glasses are highly stable against continuous X-ray irradiation and repeated heat-cooling cycles (from room temperature up to 573 K) without sacrificing their scintillation properties, thus appearing to be a potential scintillator for long-term practical applications.

Mid-Infrared Luminescence of the High Stability Perovskite CsPb1-xErxBr3-ZrF4-BaF2-LaF3-AlF3-NaF Fluoride Glass

Perovskites have been studied because of their adjustable wavelength range, high color purity, and wide color gamut. However, they still face some problems such as poor stability and insufficient infrared luminescence. The perovskite glass can improve the stability and luminescence properties of the perovskite. In this paper, a highly stable CsPb_1-xEr_xBr₃-ZBLAN fluoride glass with mid-infrared and visible light emission was prepared. The ZBLAN fluoride glass has good inertness, which can improve the stability of the CsPb_1-xEr_xBr₃ perovskite. The CsPb_1-xEr_xBr₃-ZBLAN fluoride glass can prevent the perovskite from being destroyed by water, oxygen, and laser. The Er³⁺ replaces Pb²⁺ to bond with Br^- to become the luminescent center of the CsPb_1-xEr_xBr₃-ZBLAN perovskite glass, which extends the luminescence to the mid-infrared region. In addition, its luminescent intensity is significantly higher than those of the ZBLAN-Er glass and CsPb_1-xEr_xBr₃ perovskite. After irradiation with a 365 nm UV lamp for 13 h, the luminescence intensity of the CsPb_1-xEr_xBr₃-ZBLAN perovskite glass decreases only by 10%. The EDS spectrum shows that the elements of the CsPb_1-xEr_xBr₃ perovskite are uniformly distributed in the glass matrix. The X-ray diffraction spectrum shows that the sample has both the CsPb_1-xEr_xBr₃ perovskite phase and the glass phase. This indicates that CsPb_1-xEr_xBr₃ is well crystallized in the ZBLAN glass matrix. The three parameters calculated by the Judd-Ofelt theory show that the CsPb_1-xEr_xBr₃ perovskite can increase the covalency and asymmetry around the rare earth ion Er³⁺. The transmission electron microscope can clearly see the morphological structure of the CsPb_1-xEr_xBr₃ perovskite in the ZBLAN glass matrix. The infrared Fourier transform spectroscopy shows that the sample has lower phonon energy. This proves that the sample has good infrared luminescence characteristics. Finally, the visible and infrared light sources were prepared. Under the irradiation of the 365 nm ultraviolet lamp and 980 nm laser, the perovskite glass produces green light and infrared emission.

Mn2+ induced significant improvement and robust stability of radioluminescence in Cs3Cu2I5 for high-performance nuclear battery

Fluorescent type nuclear battery consisting of scintillator and photovoltaic device enables semipermanent power source for devices working under harsh circumstances without instant energy supply. In spite of the progress of device structure design, the development of scintillators is far behind. Here, a Cs₃Cu₂I₅: Mn scintillator showing a high light yield of ~67000 ph MeV⁻¹ at 564 nm is presented. Doping and intrinsic features endow Cs₃Cu₂I₅: Mn with robust thermal stability and irradiation hardness that 71% or >95% of the initial radioluminescence intensity can be maintained in an ultra-broad temperature range of 77 K-433 K or after a total irradiation dose of 2590 Gy, respectively. These superiorities allow the fabrication of efficient and stable nuclear batteries, which show an output improvement of 237% respect to the photovoltaic device without scintillator. Luminescence mechanisms including self-trapped exciton, energy transfer, and impact excitation are proposed for the anomalous dramatic radioluminescence improvement. This work will open a window for the fields of nuclear battery and radiography.

Fluorescent-type nuclear batteries are a promising semi-permanent power source, but performance is hindered by scintillator development. Here the authors report a scintillator with high light yield and stability, which leads to improved performance.

Nanoscale Encapsulation of Perovskite Nanocrystal Luminescent Films via Plasma-Enhanced SiO2 Atomic Layer Deposition

Photoluminescence perovskite nanocrystals (NCs) have shown significant potential in optoelectronic applications in view of their narrow band emission with high photoluminescence quantum yields and color tunability. The main obstacle for practical applications is to obtain high durability against an external environment. In this work, a low temperature (50 °C) plasma-enhanced atomic layer deposition (PE-ALD) protection strategy was developed to stabilize CsPbBr₃ NCs. Silica was employed as the encapsulation layer because of its excellent light transmission performance and water corrosion resistance. The growth mechanism of inorganic SiO₂ via PE-ALD was investigated in detail. The Si precursor bis(diethylamino)silane (BDEAS) reacted with the hydroxyl groups (-OH) and thereby initiated the subsequent silica growth while having minimal influence to the organic ligands and did not cause PL quenching. Subsequently, O₂ plasma with high reactivity was used to oxidize the amine ligands of the BDEAS precursor while did not etch the NCs. The obtained CsPbBr₃ NCs/SiO₂ film exhibited exceptional stability in water, light, and heat as compared to the pristine NC film. Based on this method, a white light-emitting diode with improved operational stability was successfully fabricated, which exhibited a wide color gamut (∼126% of the National Television Standard Committee). Our work successfully demonstrates an efficient protection scheme via the PE-ALD method, which extends the applied range of other materials for stabilization of perovskite NCs through this approach.

Growth of InZnP/ZnS core/shell quantum dots with wide-range and refined tunable photoluminescence wavelengths

Owing to their environmentally friendly characteristic, InP-based quantum dots (QDs) show great potential in various fields as an alternative to Cd-based QDs. However, the current mainstream synthesis process, the (TMS)₃P-based injection method, still faces many challenges, such as the high cost of (TMS)₃P and complex temperature control. In contrast, the solvothermal method is considered to be more feasible and reproducible. Despite its potential advantages, little has been done to understand how the precursors influence the synthesis of InP QDs using the solvothermal method. In this research, InZnP/ZnS QDs were synthesized using practical phosphorus precursors (DEA)₃P or (DMA)₃P. Through the feasible regulation of zinc, indium, phosphorus and sulfur precursors, the band gap of the QDs could be widely and accurately tuned, and a much wider photoluminescence wavelength ranging from 484 nm to 651 nm could be achieved. Furthermore, InI₃ and InBr₃ contributed to the blueshift in the PL wavelengths, and the combination of (DEA)₃P, (DMA)₃P, n-DDT and t-DDT refined the PL wavelength with a small tuning gap of 5 nm.