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Despite its extensive research in photovoltaics and light emitting diodes, the charge transport properties of all‐inorganic perovskite cesium lead bromide (CsPbBr3) remain elusive. Clarification of the intrinsic charge transport of this perovskite material is highly desirable, which will help to understand its working mechanism and fabricate high performance electronic devices. Here, it is demonstrated that the phototransistors based on CsPbBr3 microplates show anomalous ambipolar transport characteristics at room temperature. The hole mobility shows light dependence, while the electron mobility is identical under various light incidence. The hole mobility increases from 0.02 cm2 V−1 s−1 (in dark conditions) to 0.34 cm2 V−1 s−1 (50 mW cm−2); while the threshold voltage is shifted by 14 V when electron is the majority charge carrier. The anomalous transport behavior can be attributed to the photovoltaic and photoconductive effects. Moreover, the device shows photoresponsivity and detectivity up to 110 mA W−1 and 4.5 × 1013 Jones, respectively, under 532 nm laser illumination. This research unveils the charge transport mechanism of CsPbBr3 perovskite, provides more evidence and will thus contribute to the perovskite electronic and optoelectronic researches. [ABSTRACT FROM AUTHOR]

Single crystal perovskites are used in solar cells, photodetectors, and other devices due to their excellent light absorption and carrier transport characteristics. However, for light‐emitting applications, photoluminescence (PL) is usually weak for MAPbBr3 (MA = CH3NH3+) single crystals (MBSCs) compared with their polycrystalline counterpart. Therefore, developing novel techniques to process MBSCs with different morphologies for PL‐related applications is greatly needed. The current strategies for making perovskite crystals are mostly based on bottom‐up method (chemical synthesis and assembling). Here, an easy method to achieve top‐down fabrication of MBSCs, i.e., femtosecond laser processing MBSC surface by controlling the laser parameters is demonstrated. The femtosecond laser processing technology can achieve two orders of magnitude enhancement under ambient conditions in PL. In addition, the processed regions also show three times enhancement in PL under nitrogen environment. It is assumed that this is mainly due to the texture based on photon recycling and light out‐coupling mechanism, and the passivation of surface recombination centers on MBSC. This study not only provides a convenient top‐down strategy to achieve a range of morphological micro‐/nanostructures with enhanced PL on MBSC surface, but also paves the way for applications of MBSCs in light emitting or PL imaging devices. Developing novel techniques to process MAPbBr3 single crystals (MBSCs) with various morphologies for photoluminescence‐related applications is highly necessary. Multi‐morphological micro‐/nanostructures induced by a top‐down fabricating technology, i.e., femtosecond laser processing, are achieved on MBSC surfaces. Dramatically‐enhanced photoluminescence of two orders of magnitude in ambient conditions and three times in nitrogen atmosphere is demonstrated, which is promising for photoluminescence‐related applications. [ABSTRACT FROM AUTHOR]

In this research, we introduce a PdSe 2 /2H-MoTe 2 heterojunction photodetector that exhibits both broadband self-powered photodetection and linear/circular polarization detection capabilities. It has a broad spectral response range (covering 375-2200 nm) and reaches a peak sensitivity at 532 nm, exhibiting a notable responsivity of 7.3 × 10 3 A/W and a substantial specific detectivity of 8.5 × 10 12 Jones. Even in the near-infrared region of 1310 nm, it still has a high responsivity of 20 A/W. The self-powered photodetection capabilities of the PdSe 2 /2H-MoTe 2 heterojunction are equally impressive, covering a broad range from 375 to 1550 nm, with a responsivity of 243 mA/W, a specific detectivity of 6.46 × 10 10 Jones, a fill factor of 0.8, and an external quantum efficiency of 56.73%. Finally, simultaneous implementation of linear/circular polarization detection on the PdSe 2 /2H-MoTe 2 heterojunction provides a powerful solution for near-infrared full-Stokes polarization detectors with high integration, miniaturization, and portability.

Broadband photodetectors have drawn intensive attention owing to their wide application prospects in optical communication, imaging, astronomy, and so on. Two-dimensional transition-metal dichalcogenides (TMDs) are considered as highly potential candidates for photodetection applications, benefiting from their excellent photoelectric properties. However, most of the photodetectors based on TMDs suffer from low performance in the near-infrared (NIR) region due to the weak optical absorption efficiency near their absorption band edge, which severely constrains their usage for broadband optoelectronics. Here, by taking advantage of the high absorption coefficient and environment-friendly property of Ag 2 S quantum dots (QDs), the hybrid of multilayer MoSe 2 /Ag 2 S QDs is demonstrated with a high-performance broadband photodetection capability (532-1270 nm). The favorable energy band alignment of MoSe 2 /Ag 2 S QDs facilitates effective separation and collection of photogenerated carriers, and the heterostructure device exhibits significant enhancement of performance compared to the bare MoSe 2 device. High responsivity, detectivity, and external quantum efficiency of 25.5 A/W, 1.45 × 10 11 Jones, and 1070% are obtained at a low working voltage of 1 V under 980 nm illumination. The responsivity of the device can reach up to 1.2 A/W at 1270 nm wavelength, which is competitive to the commercial NIR photodetectors. Meanwhile, broadband imaging capability is demonstrated. Our work may open up a facile and eco-friendly approach to construct high-performance broadband photodetectors for next-generation compact optoelectronic applications.

Background: This study explored the specific relationship between different lipid indicators and cognitive impairment and aimed to provide a reference for implementing targeted lipid regulation measures to prevent and alleviate cognitive impairment., Methods: We searched three databases (PubMed, Embase, and Web of Science) for literature related to hyperlipidaemia, lipid levels, and cognitive impairment, and used the Newcastle-Ottawa Scale to evaluate the quality of the identified literature. A meta-analysis was performed using RevMan 5.4, and the combined effect size ratio using a random-effects model (odds ratio [OR] and 95% confidence interval [CI]) was used to evaluate the association between dyslipidaemia and cognitive impairment., Results: Among initially identified 2247 papers, we ultimately included 18 studies involving a total of 758,074 patients. The results of the meta-analysis revealed that patients with hyperlipidaemia had a 1.23-fold higher risk of cognitive impairment than those with normal lipid levels (OR = 1.23, 95% CI: 1.04-1.47, p = 0.02). Further subgroup analysis showed that elevated total cholesterol (TC) levels increased the risk of cognitive impairment by 1.59-fold (OR = 1.59, 95% CI: 1.27-2.01, p < 0.0001) and were more significant in older or male patients. Moreover, elevated triglyceride levels were inversely correlated with cognitive disorders, whereas elevated low-density lipoprotein cholesterol levels were unrelated to cognitive impairment risk., Conclusions: Dyslipidaemia was strongly associated with cognitive impairment, and elevated TC levels were a risk factor for cognitive impairment. Furthermore, the damaging effects of elevated TC levels on cognition were more pronounced in older and male populations., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s). Published by IMR Press.)

A low-cross-talk and thermo-insensitive 1×4 coarse wavelength-division multiplexing device is proposed on the silicon-on-insulator platform with the help of compact Mach-Zehnder interferometers (MZIs) and slot waveguides. The compact MZIs are used to achieve wavelength-insensitive power splitting. In the phase shifters, the trade-off between the opposite thermo-optical coefficients of the Si core and SU8 cladding in the slot waveguide is used to overcome the strong thermo-optic effect of silicon. The simulated results show that the cross talk is less than -20 d B at central wavelengths and the temperature-dependent wavelength shift is reduced to ∼4.7 p m / ∘ C . For the four channels, the 1-dB and 3-dB bandwidths are ∼14 n m and ∼18 n m , respectively.

With the advantages of a moderate band gap, high carrier mobility and good environmental stability, two-dimensional (2D) semiconductors show promising applications in next-generation electronics. However, the accustomed metal-2D semiconductor contact may lead to a strong Fermi level pinning (FLP) effect, which severely limits the practical performance of 2D electronics. Herein, the interfacial properties of the contacts between a promising 2D semiconductor, PtSe 2 , and a sequence of metal electrodes are systematically investigated. The strong interfacial interactions formed in all metal-PtSe 2 contacts lead to chemical bonds and a significant interfacial dipole, resulting in a vertical Schottky barrier for Ag, Au, Pd and Pt-based systems and a lateral Schottky barrier for Al, Cu, Sc and Ti-based systems, with a strong FLP effect. Remarkably, the tunneling probability for most metal-PtSe 2 is significantly high and the tunneling-specific resistivity is two orders of magnitude lower than that of the state-of-the-art contacts, demonstrating the high efficiency for electron injection from metals to PtSe 2 . Moreover, the introduction of h -BN as a buffer layer leads to a weakened FLP effect ( S = 0.50) and the transformation into p-type Schottky contact for Pt-PtSe 2 contacts. These results reveal the underlying mechanism of the interfacial properties of metal-PtSe 2 contacts, which is useful for designing advanced 2D semiconductor-based electronics.

Purpose: Coronary artery disease (CAD) and atrial fibrillation (AF) often coexist and lead to a much higher risk of mortality in the elderly population. The aim of this study was to investigate whether the CHA 2 DS 2 -VASc score could predict the risk of death in elderly patients with CAD and AF. Methods: Hospitalized patients aged ≥65 years with a diagnosis of CAD and AF were recruited consecutively. Patients were divided into 5 groups according to the CHA 2 DS 2 -VASc score (≤2, =3, =4, =5, and ≥6). At least a 1-year follow-up was carried out for the assessment of all-cause death. Results: A total of 1,579 eligible patients were recruited, with 582 all-cause deaths (6.86 per 100 patient-years) occurring during a follow-up of at least 1 year. With the increase in the CHA 2 DS 2 -VASc score, the 1-year and 5-year survival rate decreased (96.4% vs. 95.7% vs. 94.0% vs. 86.5% vs. 85.7%, respectively, P < 0.001; 78.4% vs. 68.9% vs. 64.6% vs. 55.5% vs. 50.0%, respectively, P < 0.001). Compared with the patients with CHA 2 DS 2 -VASc score <5, for patients with CHA 2 DS 2 -VASc score ≥5, the adjusted hazard ratio for death was 1.78 (95% CI: 1.45-2.18, P < 0.001). The predictive values of the CHA 2 DS 2 -VASc score ≥5 for in-hospital (C-index = 0.66, 95% CI: 0.62-0.69, P < 0.001), 1-year (C-index = 0.65, 95% CI: 0.63-0.67, P < 0.001) and 5-year (C-index = 0.60, 95% CI: 0.59-0.61, P < 0.001) death were in comparable. Conclusion: In elderly patients with concomitant CAD and AF, the CHA 2 DS 2 -VASc score can be used to predict death with moderate accuracy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wu, Wang, Dong, Qin, Li, Yan, Guo, Feng, Zou, Wang, Du, Zhang, Ma and Yin.)

We present a chemical vapor deposition method for the synthesizing of single-crystal 1T'-MoTe 2 nanowires and the observation of one-dimensional weak antilocalization effect in 1T'-MoTe 2 nanowires for the first time. The diameters of the 1T'-MoTe 2 nanowires can be controlled by changing the flux of H 2 /Ar carrier gas. Spherical-aberration-corrected transmission electron microscopy, selected area electron diffraction and energy dispersive x-ray spectroscopy (EDS) reveal the 1T' phase and the atomic ratio of Te/Mo closing to 2:1. The resistivity of 1T'-MoTe 2 nanowires shows metallic behavior and agrees well with the Fermi liquid theory (<20 K). The coherence length extracted from 1D Hikami-Larkin-Nagaoka model with the presence of strong spin-orbit coupling is proportional to T -0.36 , indicating a Nyquist electron-electron interaction dephasing mechanism at one dimension. These results provide a feasible way to prepare one-dimensional topological materials and is promising for fundamental study of the transport properties., (© 2021 IOP Publishing Ltd.)

In this paper, we proposed a novel approach for rapid and flexible fabrication of self-driven microfluidic surface enhanced Raman scattering (SERS) chips for quantitative analysis of Hg 2+ by femtosecond laser direct writing. In contrast to traditional microfluidic chips, the microchannels of the device can drive a liquid sample flow without external driving force. The sample flow speed is tunable since the wettability and capillarity properties of the channels, which depend on the roughness and the inner diameter of the microchannels, can be controlled by optimizing the laser processing parameters. The SERS active detection sites, which exhibit high enhancement effects and fine reproducibility, were integrated through the femtosecond laser-induced periodic surface structures (LIPSS), followed by 30 nm Ag deposition. The SERS performance of the as-prepared microfluidic SERS detection chip was studied with R6G as probe molecules. The quantitative analysis of Hg 2+ was realized by simply injecting the Hg 2+ sample and the probe molecules R6G from the two inlets, separately, and collecting the SERS signal at the detection site. The lowest detection limit for Hg 2+ is 10 -9 M. It should be mentioned that this study is not only limited to Hg 2+ quantitative analysis, but is also mainly aimed to develop a new technique for the design and fabrication of novel self-driven microfluidic devices depending on practical application requirements.