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Perovskite photovoltaics, typically based on a solution-processed perovskite layer with a film thickness of a few hundred nanometres, have emerged as a leading thin-film photovoltaic technology. Nevertheless, many critical issues pose challenges to its commercialization progress, including industrial compatibility, stability, scalability and reliability. A thicker perovskite film on a scale of micrometres could mitigate these issues. However, the efficiencies of thick-film perovskite cells lag behind those with nanometre film thickness. With the mechanism remaining elusive, the community has long been under the impression that the limiting factor lies in the short carrier lifetime as a result of defects. Here, by constructing a perovskite system with extraordinarily long carrier lifetime, we rule out the restrictions of carrier lifetime on the device performance. Through this, we unveil the critical role of the ignored lattice strain in thick films. Our results provide insights into the factors limiting the performance of thick-film perovskite devices.

MoO3 is a typical transition metal oxide, which is widely used in many fields owing to its unique physicochemical properties. Current studies have shown that Carbon (C) or metallic compounds (M) can enhance its absorption properties. In this study, we employed interface engineering methods and utilized a core–shell encapsulation structure to investigate the superior electromagnetic wave absorption performance of molybdenum oxide double-layer composite materials under different coating sequences. o-MoO3/M/C (external PPy internal metal ions, ratio 1:1) and o-MoO3/C/M (external metal ions internal PPy, ratio 1:1) were synthesized by hydrothermal synthesis and pyrolysis. By comparing the absorption results of the two samples, o-MoO3/M/C is significantly better than o-MoO3/C/M. The widest absorption bandwidth is 5.28 GHz when the material (o-MoO3/M/C) thickness is 6.6 mm, with a minimum reflection loss (RLmin) of − 20.42 dB when the material thickness is 5.7 mm. [ABSTRACT FROM AUTHOR]

In-situ foam generation can effectively improve reservoir heterogeneity and enhance oil recovery. In order to solve the problems of environmental pollution and difficult demulsification of emulsion caused by chemical methods, this study selected green and foaming Pseudomonas aeruginosa (PA) to carry out foam stability test, crude oil emulsification demulsification experiment, sand-filled pipe experiment, and micromodel displacement experiment. PA bacteria can produce foam at 25–45 °C, high salinity 5%, and weak acid and weak alkali environment. The foam size is 20–100 μm, and the foam half-life is 109 min. After adding a certain amount of polymer and nanoparticles, the half-life can be increased by 14.3% –35.3%. The foam culture solution has good viscosity reduction effect and emulsification performance. After treatment, the viscosity of crude oil decreased by 96.26%, the gum content decreased by 9.474%, and the saturated hydrocarbon content increased by 11.136%. Among them, the emulsion can be well demulsified by organic acids, and the crude oil recovery rate is as high as 91.47%. The culture medium has good oil washing ability, which can improve the recovery rate of crude oil and increase the recovery rate of low permeability tube with permeability range of 8.2% × 30.8%. At the same time, the foam has good stability, deformation, and plugging ability, which can effectively improve the heterogeneity of the reservoir. The foam generated in situ by microorganisms enhances oil recovery by profile control and oil washing. [ABSTRACT FROM AUTHOR]

Microbiologically influenced corrosion (MIC) is a universal issue of significant concern in the petroleum industry, with the potential for enormous economic losses and casualties. This study focused on the effect of temperature on MIC and the corrosion mechanism. The corrosion rate, morphology, corrosion products, and microbial community composition of produced fluid samples from the Zhanjiang oilfield were measured after anaerobic culture at 30 and 60 °C for 14 days. The corrosion rate of the Z1 and Z2 samples decreased with increasing temperature, while the corrosion rate of the Z3 sample changed from light corrosion to heavy corrosion. The Z1 sample was dominated by pitting corrosion, the Z2 sample had a relatively smooth surface, and the Z3 sample was observed to have one dimensional wormhole corrosion at 60 °C. The microbial community composition by 16S ribosomal deoxyribonucleic acid (rDNA) sequence showed that the bacterial communities were dominated by Pseudomonas and Bacillus, and the archaeal communities were mainly composed of Methanothermobacter, Methanosaeta, and Candidatus Nitrosotenuis, which was prevalent in Z3 samples at 60 °C. It suggested that MIC could be caused by extracellular electron transfer and reduction of nitrate or nitrite to N2 and NH 4 + by bacteria, and utilization of CO2 to produce CH4 by archaea. Overall, the results of this study can provide comprehensive data and new insights into corrosion management strategies for oil fields. [ABSTRACT FROM AUTHOR]

Two‐step sequential deposition of perovskite films is proven efficient and compatible with large‐scale production. Nevertheless, its critically regulated environmental humidity often remains a burden, hindering its applications in reproducible fabrication of perovskite solar cells (PSCs). Herein, by introducing a water ethyl acetate (W‐EA) solution treatment before annealing, improved perovskite crystallinity and homogeneity in FA0.95‐xMAxCs0.05PbI3 films without additional composition regulation is achieved. In situ Grazing‐incidence Wide‐angle X‐ray Scattering experiments highlighted accelerated crystallization kinetics in W‐EA‐treated films, leading to high‐quality perovskite formation. PSCs based on this method reached an optimal power conversion efficiency of 25.01% and demonstrated enhanced moisture resistance, retaining 88% efficiency after 1000 h in ambient conditions. This W‐EA treatment simplifies the fabrication process, greatly reducing the need for controlled humidity, and offers insights into the role of water in perovskite film crystallization, with significant implications to produce high‐performance PSCs. [ABSTRACT FROM AUTHOR]

The receptivity phase located upstream from the neutral point might be significantly affected by local rarefaction effects (especially surface slip effects) in terms of the boundary-layer transition of near-space hypersonic vehicles. In this paper, the receptivity of a supersonic flat-plate boundary layer to freestream acoustic waves in no-slip and slip flows is analyzed using direct numerical simulations and linear stability theory. The Maxwell–Smoluchowski velocity-slip and temperature-jump boundary conditions are adopted at the wall to account for surface slip effects. A Mach 4.5 flow at different wall-cooling degrees is mainly analyzed, and another Mach-6 case is presented, both with freestream unit Reynolds number on the order of 1 × 10 6 /m. The main goal is to clarify the qualitative and quantitative influence of surface slip effects on the receptivity phase under different conditions. The results show that the receptivity mechanism in the slip flow is similar to that in the no-slip flow. That is, the mode S or F is excited near the leading edge due to synchronization with slow or fast acoustic waves, and the Mack second mode is excited further downstream after synchronization between modes S and F. However, the slip effects lead to distinctly quantitative differences in receptivity. The slip effects have little influence on the excitation of mode S or F near the leading edge but largely affect the evolution (intermodal exchange) of modes S and F as propagating downstream. Consequently, as for the receptivity to slow acoustic waves, the slip effects play a stabilizing role in receptivity when mode S is stable while a destabilizing role when mode S converts to the first mode in the upstream. As for receptivity to fast acoustic waves, as slip degree increases, the slip effects initially stabilize and then destabilize the receptivity, where the receptivity coefficient of the tested slip case can increase by 25% compared with the no-slip case. [ABSTRACT FROM AUTHOR]

Foam can effectively improve reservoir heterogeneity, increase gas–liquid flow rate, reduce viscous fingering, and help to improve sweep efficiency. This paper mainly studies the characteristics and performance of microbial foam production, and proposes an enhanced oil recovery method for profile control by in situ microbial foam production. By optimizing the carbon and nitrogen sources of the medium, Pseudomonas aeruginosa PAO1 produced single and double rhamnolipids and biogas composed of N2, CO2, and CH4, and it could also produce foam in high salt, weak acid, and weak alkali environments. Gas injection experiments were carried out using self-produced biogas, the foaming effect is good in the range of gas–liquid ratio 1:1–3:1 and gas injection speed 20–40 ml/min, which was 71.43%–91.25% more than the foam volume produced by CO2 injection, and the foam production was positively correlated with the protein concentration of the foam. In the early stage of incubation, the foam was 20–100 μm in diameter, with high protein concentration and strong foam stability, which slowed down the drainage, polymerization, and disproportionation of the liquid film of the foam system. The foam performance test results show that the foam half-lifetime is long, up to 109 min. Foam culture medium has good viscosity reduction effect, emulsifying properties and less corrosive. The displacement experiment shows that the foam generated in situ by PAO1 in the core has good stability, reproducibility, and profile control performance, which can reduce the permeability of the core to half of the initial permeability and improve the reservoir heterogeneity. Therefore, microbial in situ foam production can be an effective method to enhance oil recovery in heterogeneous reservoirs, which is low cost, low pollution, and simple operation. [ABSTRACT FROM AUTHOR]

Transformer-based methods have recently demonstrated their potential in time series forecasting problems. However, the mainstream approach, primarily utilizing attention to model inter-step correlation in the time domain, is constrained by two significant issues that lead to ineffective and inefficient multivariate forecasting. The first is that key representations in the time domain are scattered and sparse, resulting in parameter bloat and increased difficulty in capturing time dependencies. The second is that treating time step points as uniformly embedded tokens leads to the erasure of inter-variate correlations. To address these challenges, we propose a frequency-wise and variables-oriented transformer-based method. This method leverages the intrinsic conjugate symmetry in the frequency domain, enabling compact frequency domain representations that naturally mix information across time points while reducing spatio-temporal costs. Multivariate inter-correlations can also be captured from similar frequency domain components, which enhances the variables-oriented attention mechanism modeling capability. Further, we employ both polar and complex domain perspectives to enrich the frequency domain representations and decode complicated temporal patterns. We propose frequency-enhanced independent representation multi-head attention (FIR-Attention) to leverage these advantages for improved multivariate interaction. Techniques such as cutting-off frequency and equivalent mapping are used to ensure the model's lightweight nature. Extensive experiments on eight mainstream datasets show that our approach achieves first-rate satisfactory results and, importantly, requires only one percent of the spatio-temporal cost of mainstream methods. [ABSTRACT FROM AUTHOR]

BackgroundAll-inorganic perovskite solar cells have been extensively studied for their phase and thermal stability. In perovskite solar cells, the interface energy level arrangement between the hole transport layer (HTL) and the perovskite layer plays a decisive role in the performance of the device. Suitable interfacial energy level alignment is essential to facilitate the injection of photogenerated holes from perovskite into the HTL simultaneously effectively block electron transport efficiently, thus suppressing the recombination of holes with electrons.PurposeThis study aims to precisely determine the interfacial energy level alignment between CsPbI2Br and Spiro-OMeTAD experimentally.MethodsFirst of all, the Spiro-OMeTAD was deposited on CsPbI2Br film, then the interfacial electronic structure between CsPbI2Br and Spiro-OMeTAD was investigated by in situ X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. Finally, the fabricated CsPbI2Br film was characterized by synchrotron-based grazing incidence X-ray diffraction (GIXRD) and scanning electron microscope (SEM).ResultsExperimental results show that there is no detectable interaction observed at the Spiro-OMeTAD/CsPbI2Br interface where electrons accumulate due to the formed interfacial state. An interfacial dipole of 0.18 eV is formed at the interface with 0.13 eV and 0.27 eV upward energy band bending at the CsPbI2Br substrate side and the Spiro-OMeTAD side, respectively. The hole injection barrier at the interface as indicated by the gap between the CsPbI2Br valence band maximum (VBM) and the Spiro-OMeTAD highest occupied molecular orbital (HOMO) is determined to be 0.23 eV, which favours the hole injection and extraction. Meanwhile, the gap between the CsPbI2Br conduction band minimum (CBM) to the Spiro-OMeTAD lowest unoccupied molecular orbital (LUMO) known as the electron-blocking barrier is up to 1.25 eV, effectively blocking the electron transfer from CsPbI2Br to Spiro-OMeTAD with the interfacial recombination efficiently suppressed.ConclusionsIt is concluded that Spiro-OMeTAD is an excellent HTL material in CsPbI2Br-based all-inorganic perovskite solar cells. The present work also provides meaningful guidance for the tunning interfacial electronic structure between perovskite and HTLs for high-performance CsPbI2Br solar cells.