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2D Ruddlesden–Popper perovskites exhibit significant ferroelectricity due to the spontaneous polarization of organic molecules. By modulating the quantum well width in 2D Ruddlesden–Popper perovskites BA2MAn‐1PbnBr3n+1, a series of perovskites are adopted to realize adjustable polarization intensity and bandgap width. It is found that when n = 3, perovskite has the maximum polarization strength and optimal optoelectronic performance. In addition, flexible photodetectors with high mechanical stability are successfully fabricated based on n = 3 perovskite microplates. The fabricated flexible photodetectors exhibit high responsivity of 920 mA W−1 and detectivity of 1.02 × 1011 Jones, along with excellent flexibility and stability. After 3000 bending cycles, the photocurrent of n = 3 perovskites photodetector remains 81.8% of initial state. Besides, the photocurrent of n = 3 perovskites increase by 33 and 34 times after polarization at 0 and 3 V, respectively. And n = 3 perovskites exhibit a high polarization sensitivity with a current ratio of 2.09. On the basis of controllable regulation of the photocurrent through polarization, the application of flexible decoding optoelectronic devices by utilizing the correspondence between optical signals before and after polarization and binaries is achieved. These findings highlight the potential of modulating quantum well width in 2D Ruddlesden–Popper perovskites as a promising strategy for designing next‐generation flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]

To realize the advantageous combination of microelectronic integrated circuit technology and photonic technology, the development of high‐speed, low‐power, and chip‐integrated photodetection devices is extremely critical. Here, a large‐scale on‐chip integration photodetector array on a Si wafer consisting of 21×21 GaN p‐n homojunction pixels is prepared. The GaN homojunction subunit has significant photovoltaic performance at a bias voltage of 0 V, including high responsivity of 229.5 mA W−1, outstanding specific detectivity of 2.46×1013 Jones (360 nm, 45.7 µW cm−2), and fast response speed of 240/290 µs. Especially, external quantum efficiency can reach 94% in the faint UV illumination at 0 V bias. The excellent photoresponse is confirmed by finite element analysis, which is resulted from an oversized built‐in potential at the p‐n homojunction interface. For exploring potential practical applicability of the device, the full range of active pixels is statistically analyzed. It is confirmed that the small relative deviation of the GaN array is extremely favorable for obtaining high‐resolution imaging capability. Moreover, the prepared device can be used as an optical data receiver for UV optical communication. With compatibility and integrability to Si‐based optoelectronics platforms, the devices are appealing for sensing, imaging and communications. [ABSTRACT FROM AUTHOR]

Transparent diodes formed by a heterojunction between p-type CuS–ZnS and n-type ZnO thin films were fabricated by sequential chemical bath deposition and sol-gel spin coating. The diodes are transparent in the visible (≈70% at 550 nm) and exhibit a good rectifying characteristics, with If/Ir ratios of up to 800 at ±1 V, higher than most of the reported solution-processed diodes measured at a similar bias. More importantly, when operated as a self-powered (zero bias) UV photodetector, they show stable and fast (

Chalcogenide perovskites are a family of compounds related to perovskite structures or compositions, which have witnessed rapid advances in recent years. They possess favorable properties such as high stability, low toxicity, direct band gaps, good carrier transport abilities, strong light absorption, and potential luminescent properties, making them stand out in emerging applications, such as photovoltaics, photodetectors, light-emitting devices, and photocatalysts, among others. In this review, we aim to provide a comprehensive overview of the properties, synthesis, and applications of chalcogenide perovskites. First, we first survey the reported material structures/compositions and current understanding of their structural/optical/electrical properties, mechanics, magnetics, and stabilities. Furthermore, we discuss the synthesis strategies of these materials covering various material types such as powders, pellets, thin films, nanocrystals, and single crystals, with a focus on their potential applications, including photovoltaics, photodetectors, and other devices. Finally, we outline a brief conclusion and some prospects for the further research of chalcogenide perovskites, thus promoting more studies and developments in this field. This review can provide new insights into the fundamental properties and potential applications of chalcogenide perovskites, and thereby facilitating their further studies and developments. [ABSTRACT FROM AUTHOR]

Iron-based catalysts are gaining increased attention as promising and cost-effective materials for CO2 recycling. Their properties can be tuned by careful selection of the appropriate synthesis route, substrate, and catalytic system components. For the first time, a nanostructured material consisting of heterostructures of layered ferrihydrite (Fh) and hexagonal boron nitride (h-BN) nanoparticles has been obtained. Subsequent annealing ensures a uniform distribution of Fe nanoparticles (FeNPs) on the h-BN surfaces. Small Ag additions to the system lead to a significant decrease in the average size of FeNPs, presumably due to a seeding mechanism. Catalytic tests have shown that a low Ag content has a positive effect on the catalytic activity. Stability testing has demonstrated that the catalytic properties of the Fh/BN system improve over time, as does selectivity toward high-value-added hydrocarbons. Computational methods suggest a surface atomic configuration in which one Ag atom substitutes for one Fe atom in the (110) plane, resulting in better CO2 adsorption. [ABSTRACT FROM AUTHOR]

Background: The emergence of novel and efficient antibody maintenance approaches has provided more options for post‐induction treatment of advanced follicular lymphoma (FL), and further comparisons are required to determine the most clinically beneficial regimen. The authors conducted a systematic review and meta‐analysis to evaluate the maintenance or consolidation strategy. Methods: The authors performed two independent searches in PubMed, Web of Science, the Cochrane library databases, Scopus, and Embase for randomized controlled trials (RCTs) evaluating maintenance or consolidation therapy in untreated FL patients. Extracted data included the clinical characteristics, treatment regimen, progression‐free survival (PFS), overall survival (OS), and adverse effects. They then pooled the data and used a Bayesian random‐effects model to combine direct comparisons with indirect evidence. Results: The authors screened 1515 records and identified 13 eligible RCTs that assessed nine different regimens in 5681 advanced FL patients. Reconstructed individual survival data presented that obinutuzumab had the highest effect sizes and certainty of the evidence for PFS (hazard ratio, 0.43; 95% confidence interval, 0.22–0.79) and tolerability compared with observation. However, no benefit was observed in patients according to the OS, regardless of which regimen was taken. Considering other regimens, although an extended course of rituximab maintenance and consolidation therapies presented PFS benefits compared with standard rituximab maintenance, they were also associated with higher toxicity. Conclusions: Although obinutuzumab and rituximab maintenance treatment improved PFS significantly, its clinical benefit requires further validation in larger populations. Furthermore, because few trials informed each treatment comparison, research is needed to refine the understanding of this complex and rapidly evolving treatment landscape. The maintenance strategy showed a progression‐free survival (PFS) benefit in patients with advanced untreated follicular lymphoma. In comparison to other treatments, obinutuzumab had the highest effect sizes, the certainty of the evidence for PFS, and tolerability. [ABSTRACT FROM AUTHOR]

P-type transparent conducting films of nanocrystalline (CuS)x:(ZnS)1-x were synthesized by facile and low-cost chemical bath deposition. Wide angle X-ray scattering (WAXS) and high resolution transmission electron microscopy (HRTEM) were used to evaluate the nanocomposite structure, which consists of sub-5 nm crystallites of sphalerite ZnS and covellite CuS. Film transparency can be controlled by tuning the size of the nanocrystallites, which is achieved by adjusting the concentration of the complexing agent during growth; optimal films have optical transmission above 70% in the visible range of the spectrum. The hole conductivity increases with the fraction of the covellite phase and can be as high as 1000 S cm(-1), which is higher than most reported p-type transparent materials and approaches that of n-type transparent materials such as indium tin oxide (ITO) and aluminum doped zinc oxide (AZO) synthesized at a similar temperature. Heterojunction p-(CuS)x:(ZnS)1-x/n-Si solar cells were fabricated with the nanocomposite film serving as a hole-selective contact. Under 1 sun illumination, an open circuit voltage of 535 mV was observed. This value compares favorably to other emerging heterojunction Si solar cells which use a low temperature process to fabricate the contact, such as single-walled carbon nanotube/Si (370-530 mV) and graphene/Si (360-552 mV).

P-type transparent conducting films of nanocrystalline (CuS)x:(ZnS)1-x were synthesized by facile and low-cost chemical bath deposition. Wide angle X-ray scattering (WAXS) and high resolution transmission electron microscopy (HRTEM) were used to evaluate the nanocomposite structure, which consists of sub-5 nm crystallites of sphalerite ZnS and covellite CuS. Film transparency can be controlled by tuning the size of the nanocrystallites, which is achieved by adjusting the concentration of the complexing agent during growth; optimal films have optical transmission above 70% in the visible range of the spectrum. The hole conductivity increases with the fraction of the covellite phase and can be as high as 1000 S cm(-1), which is higher than most reported p-type transparent materials and approaches that of n-type transparent materials such as indium tin oxide (ITO) and aluminum doped zinc oxide (AZO) synthesized at a similar temperature. Heterojunction p-(CuS)x:(ZnS)1-x/n-Si solar cells were fabricated with the nanocomposite film serving as a hole-selective contact. Under 1 sun illumination, an open circuit voltage of 535 mV was observed. This value compares favorably to other emerging heterojunction Si solar cells which use a low temperature process to fabricate the contact, such as single-walled carbon nanotube/Si (370-530 mV) and graphene/Si (360-552 mV).