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In modern data storage and transmission, ensuring data integrity and reliability is critical due to potential losses or corruption caused by channel instability and system errors. Check codes have been developed to address these issues, allowing recovery of the original data even when errors occur. This paper provides a comprehensive analysis of the EVENODD code, a widely used parity code in error detection and correction applications. The fundamental principle of the EVENODD code relies on adding a binary check bit to ensure that the count of ones in the data string is either even or odd, depending on the desired configuration. Its implementation in Redundant Array of Independent Disks level 6 architecture highlights the code’s ability to improve data reliability by incorporating dual parity, enhancing fault tolerance in distributed systems. The advantages and limitations of EVENODD, such as its efficiency in single-bit error detection but inability to correct multi-bit errors, are examined. Additionally, comparisons are made with similar codes, including Longitudinal Redundancy Check and Cyclic Redundancy Check, to showcase their respective strengths and use cases. The paper discusses the EVENODD code’s industrial applications, particularly in satellite remote sensing and library databases, where data integrity is paramount. Future directions include optimizing the code's performance and cost-effectiveness for large- scale data storage and transmission environments, promoting secure and reliable information systems.

Perovskite light-emitting diodes (LEDs) are attracting great attention due to their efficient and narrow emission. Quasi-two-dimensional perovskites with Ruddlesden–Popper-type layered structures can enlarge exciton binding energy and confine charge carriers and are considered good candidate materials for efficient LEDs. However, these materials usually contain a mixture of phases and the phase impurity could cause low emission efficiency. In addition, converting three-dimensional into quasi-two-dimensional perovskite introduces more defects on the surface or at the grain boundaries due to the reduction of crystal sizes. Both factors limit the emission efficiency of LEDs. Here, firstly, through composition and phase engineering, optimal quasi-two-dimensional perovskites are selected. Secondly, surface passivation is carried out by coating organic small molecule trioctylphosphine oxide on the perovskite thin film surface. Accordingly, green LEDs based on quasi-two-dimensional perovskite reach a current efficiency of 62.4 cd A −1 and external quantum efficiency of 14.36%. Solution-processable halide perovskites have high luminous efficiency and excellent chemical tunability, making them ideal candidates for light-emitting diodes. Here Yang et al. achieve high external quantum efficiency of 14% in the devices by fine-tuning the phase and passivating the surface defects.

Perovskite solar cells have made significant strides in recent years. However, there are still challenges in terms of photoelectric conversion efficiency and long-term stability associated with perovskite solar cells. The presence of defects in perovskite materials is one of the important influencing factors leading to subpar film quality. Adopting additives to passivate defects within perovskite materials is an effective approach. Therefore, we first discuss the types of defects that occur in perovskite materials and the mechanisms of their effect on performance. Then, several types of additives used in perovskite solar cells are discussed, including ionic compounds, organic molecules, polymers, etc. This review provides guidance for the future development of more sustainable and effective additives to improve the performance of solar cells.

Multiferroic materials have great potential in non-volatile devices for low-power and ultra-high density information storage, owing to their unique characteristic of coexisting ferroelectric and ferromagnetic orders. The effective manipulation of their intrinsic anisotropy makes it promising to control multiple degrees of the storage “medium”. Here, we have discovered intriguing in-plane electrical and magnetic anisotropies in van der Waals (vdW) multiferroic CuCrP 2 S 6 . The uniaxial anisotropies of current rectifications, magnetic properties and magnon modes are demonstrated and manipulated by electric direction/polarity, temperature variation and magnetic field. More important, we have discovered the spin-flop transition corresponding to specific resonance modes, and determined the anisotropy parameters by consistent model fittings and theoretical calculations. Our work provides in-depth investigation and quantitative analysis of electrical and magnetic anisotropies with the same easy axis in vdW multiferroics, which will stimulate potential device applications of artificial bionic synapses, multi-terminal spintronic chips and magnetoelectric devices. Manipulating electrical and magnetic anisotropies will stimulate multi-terminal device applications. Here, the authors discover axis dependence of current rectifications, magnetic properties and magnon modes in van der Waals multiferroic CuCrP 2 S 6 .

Surface plasmonic effect of metal nanoparticles is an effective method to improve the power conversion efficiency (PCE) of solar cells. In this work, the PCE of bulk heterojunction (BHJ) polymer solar cells was improved by Au nanoparticles (NPs). The Au NPs were embedded into PEDOT:PSS hole transport layer by spin coating on the ITO substrates. The Au NPs with a diameter of ~16 nm were prepared by the micellar method using polystyrene-block-poly (2-vinylpyridine) diblock polymer. The Au NPs prepared by this method are distributed uniformly in size and without agglomeration on the substrates. From both experimental and theoretical results, it can be seen that the light absorption of the active layer was increased because of the surface plasmonic effect of Au NPs. Meanwhile, the carrier transport performance of PEDOT:PSS was enhanced with introduced Au NPs. As a result, the PCE of BHJ solar cells was improved from 2.81 to 3.25% by incorporating Au NPs.

Nb-doped β-Ga2O3 films were deposited on p-Si (100) and quartz substrates using radio frequency magnetron sputtering technology at various substrate temperatures. All the films annealed in an argon ambient. The surface morphology and crystal structure of the films were studied using atomic force microscope and x-ray diffraction technologies, and the results indicated that the film had a flat surface and a good crystal structure when the substrate temperature was 523 K. We investigated the optical properties of the samples, and the results highlight that Nb-doped β-Ga2O3 films exhibit high transmittance of above 80% to UV–visible light with a wavelength above 400 nm. Furthermore, the optical band gap of the Nb-doped β-Ga2O3 films decreases with increasing substrate temperature. The electrical characteristics show that the current is larger, and that the contact between the Ag electrode and the Nb-doped β-Ga2O3 film is an ohmic contact, when the substrate temperature is 523 K. All the results are beneficial for practical applications.

Hall-effect in semiconductors has wide applications for magnetic field sensing. Yet, a standard Hall sensor retains two problems: its linearity is affected by the non-uniformity of the current distribution; the sensitivity is bias-dependent, with linearity decreasing with increasing bias current. In order to improve the performance, we here propose a novel structure which realizes bias-free, photo-induced Hall sensors. The system consists of a semi-transparent metal Pt and a semiconductor Si or GaAs to form a Schottky contact. We systematically compared the photo-induced Schottky behaviors and Hall effects without net current flowing, depending on various magnetic fields, light intensities and wavelengths of Pt/GaAs and Pt/Si junctions. The electrical characteristics of the Schottky photo-diodes were fitted to obtain the barrier height as a function of light intensity. We show that the open-circuit Hall voltage of Pt/GaAs junction is orders of magnitude lower than that of Pt/Si, and the barrier height of GaAs is smaller. It should be attributed to the surface states in GaAs which block the carrier drifting. This work not only realizes the physical investigations of photo-induced Hall effects in Pt/GaAs and Pt/Si Schottky junctions, but also opens a new pathway for bias-free magnetic sensing with high linearity and sensitivity comparing to commercial Hall-sensors.

This article presents a compact 3 dB waveguide directional coupler with full waveguide bandwidth. It consists of a pair of rectangular waveguides with stairs structures in the coupling region. The waveguides are placed parallel to each other along their broad wall, which has a rectangular aperture array. The compact size, broad bandwidth, good in-band coupling flatness, and good return loss are achieved by using the proposed structure. For verification purposes, a prototype of the proposed coupler was designed, manufactured, and measured. The experimental results show that over the full waveguide bandwidth a return loss of input port better than 17.46 dB, coupling strength varying between −2.74 dB and −3.80 dB, power-split unbalance within 0.76 dB, and an isolation better than 20.82 dB were obtained. The length of the coupling region was only 15.82 mm.

The structural and gas-sensitive properties of n-N SnO2/κ(ε)-Ga2O3:Sn heterostructures were investigated in detail for the first time. The κ(ε)-Ga2O3:Sn and SnO2 films were grown by the halide vapor phase epitaxy and the high-frequency magnetron sputtering, respectively. The gas sensor response and speed of operation of the structures under H2 exposure exceeded the corresponding values of single κ(ε)-Ga2O3:Sn and SnO2 films within the temperature range of 25–175 °C. Meanwhile, the investigated heterostructures demonstrated a low response to CO, NH3, and CH4 gases and a high response to NO2, even at low concentrations of 100 ppm. The current responses of the SnO2/κ(ε)-Ga2O3:Sn structure to 104 ppm of H2 and 100 ppm of NO2 were 30–47 arb. un. and 3.7 arb. un., correspondingly, at a temperature of 125 °C. The increase in the sensitivity of heterostructures at low temperatures is explained by a rise of the electron concentration and a change of a microrelief of the SnO2 film surface when depositing on κ(ε)-Ga2O3:Sn. The SnO2/κ(ε)-Ga2O3:Sn heterostructures, having high gas sensitivity over a wide operating temperature range, can find application in various fields.

Photocatalytic decomposition of carbamazepine using Au nanoparticles modified β-Ga 2 O 3 film was investigated. The crystallization, morphology, optical properties, and electrical properties of the samples were investigated using XRD, SEM, UV–vis absorption spectroscopy, photoluminescence spectra, and photocurrent measurements. In the photocatalytic experiments of carbamazepine degradation, the Au nanoparticles modified β-Ga 2 O 3 films presented a better photocatalytic property than the pure β-Ga 2 O 3 film. The optical transmittance spectra verify that the present of Au nanoparticles can enhance the light harvesting and shrink the bandgap of the β-Ga 2 O 3 film. The photocurrent density and photoluminescence emission spectra indicate that the localized surface plasmon resonance of Au nanoparticles promoted the charge separation and suppressed the charge recombination of photoinduced electron–hole pairs in β-Ga 2 O 3 .