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Due to their unique photoelectric properties, nontoxic tin‐based perovskites are emerging candidates for efficient near‐infrared LEDs. However, the facile oxidation of Sn2+ and the rapid crystallization rate of tin‐based perovskites result in suboptimal film quality, leading to inferior efficiencies of tin‐based perovskite light‐emitting diodes (Pero‐LEDs). In this study, we investigate the influence of commonly used solvents on the quality of the CsSnI3 films. Remarkably, DMSO exhibits a stronger interaction with SnI2, forming a stable intermediate phase of SnI2·3DMSO. This intermediate effectively inhibits the oxidation of Sn2+ and slows down the crystallization rate, bringing in lower defect state density and higher photoluminescence quantum yield of the prepared perovskite films. Consequently, the corresponding Pero‐LEDs achieve a maximum external quantum efficiency (EQE) of 5.6%, among the most efficient near‐infrared Pero‐LEDs. In addition, the device processes ultra‐low efficiency roll‐off and high reproducibility. Our research underscores the crucial role of solvent‐perovskite coordination in determining film quality. These findings offer valuable guidance for screening solvents to prepare highly efficient and stable tin‐based perovskites. [ABSTRACT FROM AUTHOR]

Recently, lead‐free Sn‐based perovskite light‐emitting diodes (PeLEDs) have attracted wide attention due to their near‐infrared emission and environmental friendliness. However, desired Sn2+ is easily oxidized to Sn4+ in the crystallization process, resulting in defects and intrinsically p‐doped properties in the perovskite films. The uncontrollable oxidation affects the charge injection balance and radiative recombination, leading to poor device performance. Herein, a bi‐functional conductive molecular, 2,7‐bis(diphenylphosphoryl)‐9,9′‐spirobifluorene (SPPO13) with two P═O functional groups, is used to interact with perovskite to passivate defects and suppress the oxidation of Sn2+. Moreover, the SPPO13 modification layer inserted between the perovskite emitter and the electron transport layer can regulate the carrier injection and transport, thus promoting the charge balance. As a result, the high‐performance near‐infrared CsSnI3 PeLEDs with a record external quantum efficiency (EQE) of 6.60% and ultra‐low efficiency roll‐off are achieved. The work provides a novel approach to regulate defect passivation and charge transport for efficient Sn‐based PeLEDs. [ABSTRACT FROM AUTHOR]

Metal halide perovskite light‐emitting diodes (Pero‐LEDs) have gained great attention due to their promising applications in lighting and displays. However, in their conventional three‐layered sandwich structure, some undeserved carrier behaviors, such as imbalanced carrier injection, severe carrier loss, and unstable recombination zone, limit the device's performance. Herein, a four‐layered design by inserting a nickel acetate (Ni(OAc)2) interlayer between the emitter and hole‐transport layer(HTL) to manage carrier behavior and improve radiative recombination efficiency is proposed. Specifically, the Ni(OAc)2 interlayer is poorly conductive and can partially block the hole injection, making the hole‐electron injection more balanced. And the Ni(OAc)2 interlayer avoids the direct contact between the perovskite emitter and hole transporter, reducing the interfacial carrier quenching. Moreover, the Ni(OAc)2 interlayer inhibits the electron‐migrated recombination at the hole transporter interface, confining the carrier recombination zone in the emitter layer. As a result, the corresponding Pero‐LEDs achieve a maximum external quantum efficiency (EQEmax) of 24.6% with good reproducibility, showing an average EQEmax of over 20%. [ABSTRACT FROM AUTHOR]

This study is aimed at investigating the correlations of PCSK9 and LDLR gene polymorphisms as well as serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels with atherosclerosis and lipid metabolism in patients on maintenance hemodialysis (HD). A single nucleotide polymorphism at the E670G locus of the PCSK9 gene and the rs688 locus of the LDLR gene was analyzed by polymerase chain reaction–restriction fragment length polymorphism. All study subjects' blood lipid (triglyceride [TG], total cholesterol [TC], high‐density lipoprotein cholesterol [HDL‐C], and low‐density lipoprotein cholesterol [LDL‐C]) concentrations and lipoprotein(a) and PCSK9 levels were measured. The differences in blood lipid levels between different genotypes of the E670G locus of the PCSK9 gene and the rs688 locus of the LDLR gene in patients on maintenance HD with atherosclerosis were compared. Patients on maintenance HD with atherosclerosis at the E670G locus of the PCSK9 gene AG + GG genotype had higher levels of TG, TC, LDL‐C, and lipoprotein(a) than the AA genotype, and lower levels of HDL‐C than the AA genotype. Patients on maintenance HD with atherosclerosis at the rs688 locus of the LDLR gene CT + TT genotype had higher levels of TG, TC, LDL‐C, and lipoprotein(a) than the CC genotype, and lower levels of HDL‐C than the CC genotype. Serum PCSK9 contents in patients on maintenance HD with atherosclerosis were positively correlated with lipid indices (TG, TC, LDL‐C, and lipoprotein(a)) and carotid ultrasound indices (intima‐media thickness and resistance index), and negatively correlated with HDL‐C, maximum systolic blood flow velocity, and minimum diastolic blood flow velocity (all P <.05). [ABSTRACT FROM AUTHOR]

Metal halide perovskite materials are an emerging class of solution-processable semiconductors with considerable potential for use in optoelectronic devices.sup.1-3. For example, light-emitting diodes (LEDs) based on these materials could see application in flat-panel displays and solid-state lighting, owing to their potential to be made at low cost via facile solution processing, and could provide tunable colours and narrow emission line widths at high photoluminescence quantum yields.sup.4-8. However, the highest reported external quantum efficiencies of green- and red-light-emitting perovskite LEDs are around 14 per cent.sup.7,9 and 12 per cent.sup.8, respectively--still well behind the performance of organic LEDs.sup.10-12 and inorganic quantum dot LEDs.sup.13. Here we describe visible-light-emitting perovskite LEDs that surpass the quantum efficiency milestone of 20 per cent. This achievement stems from a new strategy for managing the compositional distribution in the device--an approach that simultaneously provides high luminescence and balanced charge injection. Specifically, we mixed a presynthesized CsPbBr.sub.3 perovskite with a MABr additive (where MA is CH.sub.3NH.sub.3), the differing solubilities of which yield sequential crystallization into a CsPbBr.sub.3/MABr quasi-core/shell structure. The MABr shell passivates the nonradiative defects that would otherwise be present in CsPbBr.sub.3 crystals, boosting the photoluminescence quantum efficiency, while the MABr capping layer enables balanced charge injection. The resulting 20.3 per cent external quantum efficiency represents a substantial step towards the practical application of perovskite LEDs in lighting and display.A strategy for managing the compositional distribution in metal halide perovskite light-emitting diodes enables them to surpass 20% external quantum efficiency--a step towards their practical application in lighting and displays., Author(s): Kebin Lin [sup.1] , Jun Xing [sup.2] , Li Na Quan [sup.3] , F. Pelayo García de Arquer [sup.3] , Xiwen Gong [sup.3] , Jianxun Lu [sup.1] , Liqiang [...]