Stability issues are the key challenges for commercialization of PSCs. Different stability issues including modification of the structural design and material, fabrication process should be considered and improved to improve the stability of PSCs.

Recent achievements, based on lead (Pb) halide perovskites, have prompted comprehensive research on low-cost photovoltaics, in order to avoid the major challenges that arise in this respect: Stability and toxicity. In this study, device modelling of lead (Pb)-free perovskite solar cells has been carried out considering methyl ammonium tin bromide (CH₃NH₃SnBr₃) as perovskite absorber layer. The perovskite structure has been justified theoretically by Goldschmidt tolerance factor and the octahedral factor. Numerical modelling tools were used to investigate the effects of amphoteric defect and interface defect states on the photovoltaic parameters of CH₃NH₃SnBr₃-based perovskite solar cell. The study identifies the density of defect tolerance in the absorber layer, and that both the interfaces are 10¹⁵ cm⁻³, and 10¹⁴ cm⁻³, respectively. Furthermore, the simulation evaluates the influences of metal work function, uniform donor density in the electron transport layer and the impact of series resistance on the photovoltaic parameters of proposed n-TiO₂/i-CH₃NH₃SnBr₃/p-NiO solar cell. Considering all the optimization parameters, CH₃NH₃SnBr₃-based perovskite solar cell exhibits the highest efficiency of 21.66% with the V_oc of 0.80 V, J_sc of 31.88 mA/cm² and Fill Factor of 84.89%. These results divulge the development of environmentally friendly methyl ammonium tin bromide perovskite solar cell.

CdS thin films were deposited by three different processes; close spaced vapour transport (CSVT), chemical bath deposition (CBD), and sputtering technique on ITO coated glasses and their structural and optical properties were investigated through XRD, SEM, EDX and UV-Vis spectrometry, respectively. The as-grown films are annealed at 400°C and 500°C for 30 min in air and the change in structural properties with the thermal stress were also investigated. The crystallite grain size, lattice constant, microstrain and dislocation densities of the films are quite different in these processes as observed from XRD analysis. The highest crystallinity is observed for sputtered CdS thin films. However, the crystalline property of CBD and sputtered CdS increases with the thermal annealing, while CSVT-CdS loses its crystalline form. No significant grain changes are observed for thermally annealed CdS thin films but some cracked lines are observed in CBD and CSVT CdS thin films from SEM images. The absorbance in the visible wavelength decreased for annealed CdS thin films, which might be due to fact that films are becoming denser followed by thermal annealing. Significant blue shifts observed for thermally annealed CdS thin films have been found from all processes. The band gap found for as-grown CSVT-CdS is 2.44 eV, for CBD-CdS is 2.38 eV and for sputtered-CdS is 2.42 eV. The disorder of phonon states in the films are observed from Urbach's tail. The absorption edges due to the exciton–phonon interaction or electron-phonon interaction are also observed from the values of steepness parameter

As a contribution to the graphene-based nanoferrite composites, this article is intended to present Mn, Co, and Co-Mn nanoferrites for the preparation and investigation of such samples. Nanoparticles of Co ferrite, Mn ferrite, and Co-Mn ferrite were chemically synthesized by the coprecipitation method. The composites of ferrite/graphene were made by incorporating weight ratios of 25% graphene to 75% ferrite. Various structural and characterizing investigations of ferrite samples and ferrite/graphene composites were performed, including XRD, EDX, SEM, VSM hysteresis loops, AC conductivity, and dielectric behavior. The investigations ensured the formation of the intended nanoferrite powders, each having a single-phase crystal structure with no undesired phases or elements. All samples exhibit a soft magnetic behavior. They show a semiconducting behavior of AC electrical conductivity as well. This was proved by the temperature dependence of the AC’s electrical conductivity. Whereas the dielectric function and loss tangent show an expected, well-explained behavior, the ferrite/graphene composite samples have lower saturation magnetization values, lower AC conductivity, and dielectric constant values than the pure ferrites but still have the same behavior trends as those of the pure ferrites. The values obtained may represent steps on developing new materials for expected applications, such as manufacturing supercapacitors and/or improved battery electrodes.

The benefits and drawbacks of various technologies, as well as the scope of their application, are thoroughly discussed. The use of anonymity technology and differential privacy in data collection can aid in the prevention of attacks based on background knowledge gleaned from data integration and fusion. The majority of medical big data are stored on a cloud computing platform during the storage stage. To ensure the confidentiality and integrity of the information stored, encryption and auditing procedures are frequently used. Access control mechanisms are mostly used during the data sharing stage to regulate the objects that have access to the data. The privacy protection of medical and health big data is carried out under the supervision of machine learning during the data analysis stage. Finally, acceptable ideas are put forward from the management level as a result of the general privacy protection concerns that exist throughout the life cycle of medical big data throughout the industry.

The popularization of electronic clinical medical records makes it possible to use automated methods to extract high-value information from medical records quickly. As essential medical information, oncology medical events are composed of attributes that describe malignant tumors. In recent years, oncology medicine event extraction has become a research hotspot in academia. Many academic conferences publish it as an evaluation task and provide a series of high-quality annotation data. This article aims at the characteristics of discrete attributes of tumor-related medical events and proposes a medical event. The standard extraction method realizes the combined extraction of the primary tumor site and primary tumor size characteristics, as well as the extraction of tumor metastasis sites. In addition, given the problems of the small number and types of annotation texts for tumor-related medical events, a key-based approach is proposed. A pseudo-data-generation algorithm that randomly replaces information in the whole domain improves the transfer learning ability of the standard extraction method for different types of tumor-related medical event extractions. The proposed method won third place in the clinical medical event extraction and evaluation task of the CCKS2020 electronic medical record. A large number of experiments on the CCKS2020 dataset verify the effectiveness of the proposed method.