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In this paper, a FeCoNiCuTi high entropy alloy (HEA) was heat treated at 950 °C for different time durations. After heat treatment for different lengths of time, the FeCoNiCuTi HEA exhibited good thermal stability, and its crystal structure maintained its FCC + Laves phase structure. The magnetic and mechanical properties of the alloy were obviously improved, the saturation magnetization was increased by 33% to 51.7 emu·g−1, and the coercivity had no significant change. After heat treatment for 10 h, the maximum strain was 16.5%, which is approximately 5 times that of the as-cast alloy.

Using mixed-halide perovskite quantum dots (QDs), with facile spectrum adjustment and extremely high color purity, is one of the most promising ways to achieve blue emission. Nevertheless, the substantial trap states and halide migration-induced phase separation enhance the instability of QDs, which seriously restricts their practical application. To overcome these issues, we creatively develop a strategy for in situ passivation based on a small organic molecule, diphenylphosphorylhydroxylamine (DPH). The strong coordination and hydrogen bonds work in concert to regulate the crystallization process of QDs and saturate vacancy defects to form a ligand-rich surface, thereby achieving more efficient exciton recombination. The resulting QDs are resistant to stronger external stimulation. Thanks to the effective passivation of DPH, the obtained blue PeLEDs with 478 nm emission exhibit extremely high color purity (full width at half maximum of 18 nm) and a maximum external quantum efficiency (EQE) of up to 4.88%. In parallel, the spectrum remains unchanged at an operating voltage of 8 V. This work provides a feasible method for realizing efficient and spectrally stable blue PeLEDs. [ABSTRACT FROM AUTHOR]

Blue‐emitting perovskite nanocrystals (NCs) are important components of high‐definition display device, but their instability to light and moisture severely hinders the commercial application. Here, a dual‐site passivation strategy is proposed and the halogen–halogen bond to surface capping molecules is applied. The bi‐functional molecule with a fluorine group and carboxyl group on the phenyl ring, would form a shell‐like molecular structure covering the nanocrystal surface at halogen and lead site via halogen‐halogen bond and coordination effect, respectively. Considering the binding strength and acid dissociation constant of several fluoro acids, the optimal optical properties and film stability confirm the para‐fluorobenzoic acid molecule provides the most effective protection for initial perovskite products account for their stronger anchoring affinity and more comprehensive surface coverage. Consequently, this work sheds light on the molecular functionality and configuration are crucial for surface properties of perovskite NCs. [ABSTRACT FROM AUTHOR]

In the era of intelligence, the output colors of foundational phosphors are expected to be controlled by programs, while current activators‐determined afterglow candidates with fixed spectral channel have limitations in creating customized colors. Here, a long‐lived warm‐white emission is successfully demonstrated originating from self‐trapped excitons (STEs) in non‐toxic Cs2NaInCl6:Ag,Bi, ranging from 400 to 850 nm, of which the afterglow color can be easily customized using filters. This investigation indicates that 3% of Ag alloying breaks the dark STEs and introduces traps for efficient afterglow, while 3% Bi doping further improves the quantum yield to ≈100% and greatly enhances afterglow by ≈100‐fold compared with the initial intensity, allowing for an impressive afterglow persistence of over 20,000 s. Intriguingly, the self‐trapped defect bands from Jahn‐Teller distortions are prolonged from hundreds of femtoseconds to several hours, and they are first detected in the steady‐state absorption spectra after the cessation of excitation sources, contributing to the concluded dynamic afterglow model for STEs. And its intelligent application is corroborated by designed multi‐channel information system. These findings offer a novel scheme for understanding dynamic luminescence of STEs and supply an exemplification of designing white afterglow phosphors. [ABSTRACT FROM AUTHOR]

In view of problem of short transmission distance and high cost of existing point to point digital communications system, multi-channel digital audio communication system based on visible light transmission was designed and implemented by use of white LED. The system combines audio codec chip of TP3067 to implement multiplexing transmission of multi-channel audio signals, and uses FPGA as the main controller to control time slot of encoder signals. Experimental results show that the system can achieve transfer rate of up to 2.048 Mbit/s, and audio signal of up to 32-channels can be transmitted stably.

Mn2+ dopants introduce a new emission center in semiconductor luminescent materials, endowing them promising photoluminescence (PL) properties, such as a wide color tuning range, reversible color change, reduced self‐absorption etc. Recently, rapid development of Mn2+ doped metal halide perovskites (MHPs) promote their promising applications in displays, photovoltaics, scintillators, etc. The emission color, luminous efficiency, and energy transfer pathway of doped perovskites are affected by condition of host lattice that accommodates Mn2+ ions. In this review, the optical properties determined by host materials with diverse geometries involving perovskite nanocrystals and perovskite derivatives is focused on, and the possible energy transfer routes in different doping systems are analyzed. An overview of recent advances of different doped systems with assigned emission channels together with the influence factors, strategies to enhance PL intensity and finally potential applications are summarized. To the end, the underlying challenges and possible solutions for further research in Mn doped perovskites are proposed. [ABSTRACT FROM AUTHOR]

Recently, metal-halide perovskites have rapidly emerged as efficient light emitters with near-unity quantum yield and size-dependent optical and electronic properties, which have attracted considerable attention from researchers. However, the ultrafast nucleation rate of ionic perovskite counterparts severely limits the in-depth exploration of the growth mechanism of colloidal nanocrystals (NCs). Herein, we used an inorganic ligand nitrosonium tetrafluoroborate (NOBF 4 ) to trigger a slow post-synthesis transformation process, converting non-luminescent Cs 4 PbBr 6 NCs into bright green luminescent CsPbBr 3 NCs to elucidate the concrete transformation mechanism via four stages: (i) the dissociation of pristine NCs, (ii) the formation of Pb-Br intermediates, (iii) low-dimensional nanoplatelets (NPLs) and (iv) cubic CsPbBr 3 NCs, corresponding to the blue-to-green emission process. The desorption and reorganization of organic ligands induced by NO + and the involvement of BF 4 - in the ligand exchange process played pivotal roles in this dissolution-recrystallization of NCs. Moreover, controlled shape evolution from anisotropic NPLs to NCs was investigated through variations in the amount of NOBF 4 . This further validates that additives exert a decisive role in the symmetry and growth of nanostructured perovskite crystals during phase transition based on the ligand-exchange mechanism. This finding serves as a source of inspiration for the synthesis of highly luminescent CsPbBr 3 NCs, providing valuable insights into the chemical mechanism in post-synthesis transformation.