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Cs2SnCl6 perovskite has recently attracted attention as a promising optoelectronic material owing to its better stability and reduced toxicity than its lead counterparts. However, its luminescence performance hardly satisfies the requirements. Hence, a series of Bi3+-doped Cs2SnCl6 (Cs2SnCl6:Bi3+) with enhanced luminescence were synthesized by a solution-phase route. The results show that the initial concentration of Sn2+ can adjust the nucleation density and the quality of the crystal nucleus growth, which will affect the Bi3+ doping amount, crystal morphology, and photophysical properties of Cs2SnCl6:Bi3+. Cs2SnCl6:Bi3+ shows excellent stability in the atmosphere with a photoluminescence (PL) of around 456 nm and a photoluminescence quantum yield (PLQY) of 31%. The luminescence performance results from [BiSn4+3+ + VCl] defects caused by the Bi3+ doping. The blue LED based on the Cs2SnCl6:Bi3+ phosphor exhibits a long life of about 120 h and a Commission Internationale de L'Eclairage (CIE) color coordinates of (0.14, 0.11). This work demonstrates a strategy for Bi-doped perovskites with good stability. This investigation will facilitate the development of Cs2SnCl6:Bi3+ for blue LED applications.

Accurate and efficient screening of retired lithium-ion batteries from electric vehicles is crucial to guarantee reliable secondary applications such as in energy storage, electric bicycles, and smart grids. However, conventional electrochemical screening methods typically involve a charge/discharge process and usually take hours to measure critical parameters such as capacity, resistance, and voltage. To address this issue of low efficiency for battery screening, scanned X-ray Computed Tomography (CT) cross-sectional images in combination with a computational image recognition algorithm have been employed to explore the gradient screening of these retired batteries. Based on the Structural Similarity Index Measure (SSIM) algorithm with 2000 CT images per battery, the calculated CT scores are closely correlated with their internal resistance and capacity, indicating the feasibility of CT scores to sort retired batteries. We find out that when the CT scores are larger than 0.65, there is high potential for a secondary application. Therefore, this pioneering and non-destructive CT score method can reflect the internal electrochemical properties of these retired batteries, which could potentially expedite the battery reuse industry for a sustainable energy future.

All-inorganic CsPbI2Br shows high thermal stability for promising application in perovskite solar cells (PSCs). The performance of PSCs is significantly affected by their morphology and crystallinity induced by compositional ratio, solvent/anti-solvent engineering and post thermal annealing. In this study, the compositional ratio effect of two precursors, PbI2 and CsBr, on the power conversion efficiency (PCE) of a device with ITO/SnO2/CsPbI2Br/Spiro-MeOTAD/Au structure was investigated. With the assistance of anti-solvent chlorobenzene, perovskite with a PbI2 : CsBr ratio of 1.05 : 1 showed a high quality thin film with higher crystallinity and larger grain size. In addition, the molar ratio of precursors PbI2 and CsBr improved the PCE of the PSCs, and the PSCs fabricated using the perovskite with an optimal ratio of PbI2 and CsBr exhibited a PCE of 13.34%.

Monolayer tungsten disulfide (WS2) with a direct band gap of ca. 2.0 eV and stable properties has been a hotspot in two-dimensional (2D) nanoelectronics and optoelectronics. However, it remains challenging to successfully prepare monolayer WS2. In this paper, we report the chemical vapor deposition (CVD) growth behavior of hexagonal WS2 monolayers by using WS2 powders and sodium triosulfate (Na2S2O3) as precursors. We observed the Na2S2O3 has a significant effect on the WS2 triangular and leaf-like shapes. In addition, based on proposed S-termination and W-termination theory, the growth mechanisms for different shapes of WS2 were discussed.

Cs

All-inorganic CsPbI

Monolayer tungsten disulfide (WS