Perovskite solar cells (PSCs) have attracted extensive attention due to their outstanding optoelectronic properties. However, interfacial carrier losses and defect-induced instability remain the key bottlenecks that limit their efficiency and operational lifetime. In this work, we propose a synergistic interfacial engineering strategy using two functional modifications of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and 2-thiophe-neethylam monium chloride (TEACl). F4TCNQ is introduced into the hole transport layer to enhance charge extraction efficiency, while TEACl is incorporated into the perovskite layer to passivate defects and regulate crystal growth. F4TCNQ effectively reduces the hole extraction barrier, improves the conductivity of PTAA, and better aligns energy levels with the perovskite layer. Meanwhile, TEACl mitigates non-radiative charge carrier recombination by filling halide vacancies with Cl-and coordinating undercoordinated Pb2+ ions with TEA+, thereby extending the lifetime of photoexcited carriers. Benefiting from this dual-modification strategy, the device achieves a power conversion efficiency (PCE) of 20.79 % and exhibits excellent thermal and storage stability. This study provides a viable method for high-efficiency and stable PSCs.

In this paper, the quasi-2D green perovskite BA(2)Cs(4)Pb(5)Br(16) film passivated by the CH3O-PEABr is reported to realize nonradiative defect suppressing. The passivated BA(2)Cs(4)Pb(5)Br(16) film has a large exciton binding energy (74.9 meV), which is conducive to efficient radiation recombination. Time-resolved photoluminescence and ultrafast transient absorption spectroscopy show that the carrier lifetime is effectively prolonged after CH3O-PEABr passivation, indicating photoluminescence enhancement is attributed to the nonradiative defect suppressing. Finally, an electroluminescent green light-emitting diodes device is fabricated based on the CH3O-PEABr-passivated BA(2)Cs(4)Pb(5)Br(16) thin film, the maximum external quantum efficiency can be 19.47%. The results indicate that the CH3O-PEABr passivated BA(2)Cs(4)Pb(5)Br(16) thin film can be a promising material for the high-performance green light-emitting diodes.

In this work, a label-free, and highly sensitive THz biomedical sensor based on metamaterial structure is proposed and analyzed for the fast detection of COVID-19 virus. The reported design can differentiate between normal and infected samples with different dielectric constants. Moreover, it can be used to determine the degree of infection even at very low concentrations of the COVID-19 virus. The design parameters such as geometrical dimensions and type of materials are studied and analyzed in order to maximize the sensor performance. The proposed biomedical sensor has a high sensitivity of 2554 and 1216 GHz RIU-1 around resonance mode frequencies of 5.15 THz and 5.88 THz with quality factor values of 14.34, and 14.78, respectively. Further, the suggested biomedical sensor can detect and monitor other COVID variants like omicron, delta, beta, and alpha variants. Thus, the proposed biomedical sensor significantly enhances healthcare capabilities for patients globally.

Triple cation(Csx(MA0.17FA0.83)1-xPb(I0.83Br0.17)3) perovskites have attracted extensive attention owing to their excellent stability and photovoltaic performance. In this work, an efficient perovskite solar cell with a structure of TiO2/Csx(MA0.17FA0.83)1-xPb(I0.83Br0.17)3 (CsFAMA)/ CuSCN was proposed and optimized theoretically using the solar cell simulator capacitance software (SCAPS-1D). This study optimized the parameters of the absorber layer, such as the thickness, doping density, defect density and bandgap. In addition, the electron transport layer (ETL) and the hole transport layer (HTL) are optimized by varying their electron affinity, thickness and doping density. It was found that the optimization of the absorber layer thickness and doping density provided a significant improvement in the efficiency of the device, while the parameters of both ETL and HTL showed minor influence on the device performance. Moreover, the operation temperature was discussed to provide further insight concerning the device performance. It showed that an increase of the operation temperature from 300 to 700 K resulted in reduction of device performance. And the CsFAMA-based device showed the highest power conversion efficiency (PCE) of 28.66% at 300 K with fill factor (FF) of 83.18%, open circuit voltage (Voc) of 1.48 V and short circuit current density (Jsc) of 23.27 mA/cm2. The optimized values of the absorber thickness, defect density and doping density were found to be 500 nm, 2.6 x 1013 cm -3 and 1 x 1016 cm -3, respectively. The findings of this study suggest CsFAMA-based absorber materials can play an important role in high efficiency perovskite solar cells with excellent stability.

In this study, tandem solar cell (SC) based on MAPbI 3 -prevoskiteISi-nanowires (P|Si-NWs) structure is proposed and numerically investigated. The simulation results are calculated using the finite difference time domain (FDTD) method. The optical efficiency of the proposed tandem SC is increased to 40% compared to 37.5% for the counterpart planar tandem structure. This is owing to the high absorption coefficient and optimum MAPbI3 band gap of the perovskite SC. Further, the supported wave-guided modes and excited Bloch modes due to the periodic SiNWs help increase the optical absorption through the suggested SC. Further, the perovskite thickness can be controlled to efficiently balance the photo-generated current with the bottom Si layer with improved output efficiency. The J ph of the reported SC is equal to 13.1 mA/cm 2 with an enhancement of 37.5% relative to planar P|Si structure. Consequently, the proposed tandem PSiNWs structure offers better electrical performance with reduced Si-material and low manufacturing cost.

Previous polarization imaging methods tend to assume that the degree of polarization of the target reflected light is a constant, while the targets with nonuniform polarization characteristics are less considered. The required background area or prior knowledge hinders the practical application of underwater polarization imaging technology. In this paper, we analyzed the basic physical model of underwater imaging, and proposed a new underwater polarization de-scattering method by considering orthogonal polarization decomposition of both the target reflected and backscattered light. The polarized-difference intensity of the backscattered light can be directly calculated from the polarization orientation angle of the two horizontal decomposition components. Meanwhile, a low-pass filter was used to suppress noise and globally evaluate the degree of polarization of the backscattered light. The proposed method can automatically distinguish the underwater targets polarization characteristics, and no background area or any prior information is required. The laboratory simulation experimental results demonstrate that this method can effectively improve the quality of underwater images under different conditions.

Abstract The optimization of charge transport with electron‐hole separation directed toward specific redox reactions is a crucial mission for artificial photosynthesis. Bismuth vanadate (BiVO4, BVO) is a popular photoanode material for solar water splitting, but it faces tricky challenges in poor charge separation due to its modest charge transport properties. Here, a concept of the external electron transport layer (ETL) is first proposed and demonstrated its effectiveness in suppressing the charge recombination both in bulk and at surface. Specifically, a conformal carbon capsulation applied on BVO enables a remarkable increase in the charge separation efficiency, thanks to its critical roles in passivating surface charge‐trapping sites and building external conductance channels. Through decorated with an oxygen evolution catalyst to accelerate surface charge transfer, the carbon‐encased BVO (BVO@C) photoanode manifests durable water splitting over 120 h with a high current density of 5.9 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (RHE) under 1 sun irradiation (100 mW cm−2, AM 1.5 G), which is an activity‐stability trade‐off record for single BVO light absorber. This work opens up a new avenue to steer charge separation via external ETL for solar fuel conversion.

Classical stochastic electromagnetic field assumes that the number of steps is infinite, but in practice, the number of steps for random walk is limited, even though the number of steps is large. Therefore, the statistical properties of finite-step random phasor sums are different from those of classical ones. As an example, the negative exponential probability density function of classical intensity speckles is not suitable for speckles with limited steps. In some applications, including but not limited to synthetic-aperture radar (SAR) imagery, wireless communication and wavelet analysis, when the probability density function of the classical speckle is used to calculate, the acquired result is often biased, and can’t provide appropriate estimation with reasonable accuracy. In this paper, we make the statistical analysis of the Stokes parameters of the random polarization phasor sums with a limited number of steps. The statical properties for the stochastic optical fields generated with a limited number of steps are presented with different applications in optical engineering

In order to study the unique nonlinear optical properties and excitation mechanism, Cu-doped zinc oxide nanorods were excited by femtosecond pulsed laser. Under the excitation of 750 nm, the second harmonic peak is almost ignore meanwhile only the exciton peak and Cu doping re-lated peak. The increase of the excitation intensity leads to a nonlinear increase of the intensity of the two emission peaks. The position of exciton peak exhibits a red shift meanwhile the position of defect peak does not move. If the excitation intensity further increases, the intensity of the defect re-lated emission will decrease and the intensity of the exciton emission will increase continuously. When the excitation wavelength increases to 760 nm, the fluorescence spectrum of the sample can be clearly recognized the coexistence of the second harmonic peak and the exciton emission as well as the defect related emission. With the increasing of the excitation wavelength, the intensity of the second harmonic increases and the intensity of exciton emission and defect related emission de-crease. At the excitation wavelengths of 790 nm and 800 nm, the exciton emission and defect related emission cannot be found, and the nonlinear spectrum is dominated by second harmonic generation. By selecting the appropriate excitation wavelength and excitation intensity, the transition of theluminescent color display can be realized, which makes Cu-doped ZnO nanorods as the potential of all-optical display.

肌酸酶(CRE)是临床检测血液和尿液中肌酐的关键酶之一.作者成功地从烟草节杆菌23710 (Arthrobacter nicotianae 23710)中克隆了CRE基因,并实现了CRE在Escherichia coli BL21 (DE3)中的表达.经过硫酸铵分级沉淀、阴离子交换色谱、分子筛后得到了较纯的重组CRE,比酶活达到了20.25 U/mg.重组CRE对于螯合剂EDTA、表面活性剂(Tween20,和Triton X-100)以及常用的防腐剂NaN3有很好的耐受性.

Effective and bright light-emitting-diodes (LEDs) have attracted broad interests in fundamental research and industrial application, especially on short wavelength LEDs. In this paper, a well aligned ZnO nanorod arrays grown on the p-GaN substrate to form a heterostructured light-emitting diode and Al nanoparticles (NPs) were decorated to improve the electroluminescence performance. More than 30-folds enhancement of the electroluminescence intensity was obtained compared with the device without Al NPs decoration. The investigation on the stable and transient photoluminescence spectraof the ZnO nanorod arrays before and after Al NPs decoration demonstrated that the metal surface plasmon resonance coupling with excitons of ZnO leads to the enhancement of the internal quantum efficiency (IQE). Our results provide aneffective approach to design novel optoelectronic devices such as light-emitting diodes and plasmonic nanolasers.

The strain-induced magnetoresistance (MR) has been investigated in detail by simulating the spin-rotation in spin-valve structures. The results show that the strain-induced anisotropy can be utilized to control the relative orientation of the spins in the two adjacently arranged ferromagnetic layers because each layer responds to the external strain differently, thus the strain-induced MR is exhibited. The MR dependencies on magnitude and orientation of strain have been described in detail. Especially, we highlight first the behavior of MR induced by the direction of strain with respect to the magnetic easy axis. In addition, the effects of some magnetic parameters on strain-induced MR have been presented, respectively. This work clarifies further the strain-induced MR mechanism to provide a theoretical support both for a number of experiments and for the design of the MR strain sensors.