Tin perovskite solar cells (TPSCs) have triggered intensive research as a promising candidate for lead-free perovskite solar cells. However, it is still challenging to obtain efficient and stable ...TPSCs because of the low defects formation energy and the oxidation of bivalent tin; Here, we report a TPSC with a stable amorphous-polycrystalline structure, which is composed of a tin triple-halide amorphous layer and cesium-formamidinium tin iodide polycrystals. This structure effectively blocks the outside oxygen, moisture and also suppresses the ion diffusion inside the devices. In addition, its energy level benefits the charge extraction and transport in TPSCs. This design enabled us to obtain the certified quasi-steady-state efficiency over 10% for TPSCs from an accredited certification institute. The cell was stable, maintaining 95% of the initial PCE after operation at the maximum power point under AM 1.5 G simulated solar light (100 mWcm
) for 1000 hours.
Here we report a solution-processing strategy to stabilize the perovskite-based heterostructure. Strong Pb-Cl and Pb-O bonds formed between a CH(NH
)
CH
NH
Pb
I
film with a Pb-rich surface and a ...chlorinated graphene oxide layer. The constructed heterostructure can selectively extract photogenerated charge carriers and impede the loss of decomposed components from soft perovskites, thereby reducing damage to the organic charge-transporting semiconductors. Perovskite solar cells with an aperture area of 1.02 square centimeters maintained 90% of their initial efficiency of 21% after operation at the maximum power point under AM1.5G solar light (100 milliwatts per square centimeter) at 60°C for 1000 hours. The stabilized output efficiency of the aged device was further certified by an accredited test center.
Tin‐based perovskites with narrow bandgaps and high charge‐carrier mobilities are promising candidates for the preparation of efficient lead‐free perovskite solar cells (PSCs). However, the ...crystalline rate of tin‐based perovskites is much faster, leading to abundant trap states and much lower open‐circuit voltage (Voc). Here, hydrogen bonding is introduced to retard the crystalline rate of the FASnI3 perovskite. By adding poly(vinyl alcohol) (PVA), the OH…I− hydrogen bonding interactions between PVA and FASnI3 have the effects of introducing nucleation sites, slowing down the crystal growth, directing the crystal orientation, reducing the trap states, and suppressing the migration of the iodide ions. In the presence of the PVA additive, the FASnI3–PVA PSCs attain higher power conversion efficiency of 8.9% under a reverse scan with significantly improved Voc from 0.55 to 0.63 V, which is one of the highest Voc values for FASnI3‐based PSCs. More importantly, the FASnI3–PVA PSCs exhibit striking long‐term stability, with no decay in efficiency after 400 h of operation at the maximum power point. This approach, which makes use of the OH…I− hydrogen bonding interactions between PVA and FASnI3, is generally applicable for improving the efficiency and stability of the FASnI3‐based PSCs.
The OH…I− hydrogen bonding interactions between poly(vinyl alcohol) (PVA) and FASnI3 have the effects of introducing nucleation sites, slowing down crystal growth, directing the crystal orientation, reducing the trap states, and suppressing the migration of the ions. By adding PVA, the FASnI3–PVA perovskite solar cells attain improved power conversion efficiency and stability.
A systematic investigation of multiscale pore structure in organic‐rich shale by means of the combination of various imaging techniques is presented, including the state‐of‐the‐art ...Helium‐Ion‐Microscope (HIM). The study achieves insight into the major features at each scale and suggests the affordable techniques for specific objectives from the aspects of resolution, dimension, and cost. The pores, which appear to be isolated, are connected by smaller pores resolved by higher‐resolution imaging. This observation provides valuable information, from the microscopic perspective of pore structure, for understanding how gas accumulates and transports from where it is generated. A comprehensive workflow is proposed based on the characteristics acquired from the multiscale pore structure analysis to simulate the gas transport process. The simulations are completed with three levels: the microscopic mechanisms should be taken into consideration at level I; the spatial distribution features of organic matter, inorganic matter, and macropores constitute the major issue at level II; and the microfracture orientation and topological structure are dominant factors at level III. The results of apparent permeability from simulations agree well with the values acquired from experiments. By means of the workflow, the impact of various gas transport mechanisms at different scales can be investigated more individually and precisely than conventional experiments.
Key Points:
A combination of various imaging techniques is applied to investigate the multiscale pore structure in organic‐rich shale
The pores, which appear to be isolated, are connected by smaller pores resolved by higher‐resolution imaging
A multilevel simulation workflow is proposed to simulate the gas transport process, which agrees well with the experimental result
Perovskite solar cells (PSCs) are a promising third‐generation photovoltaic (PV) technology developed rapidly in recent years. Further improvement of their power conversion efficiency is focusing on ...reducing the non‐radiative charge recombination induced by the defects in metal halide perovskites. So far, defect passivation by the organic small molecule has been considered as a promising approach for boosting the PSC performance owing to their large structure flexibility adapting to passivating variable kinds of defect states and perovskite compositions. Here, the recent progress of defect passivation toward efficient and stable PSCs was reviewed from the viewpoint of molecular structure design and device performance. To comprehensively reveal the structure‐performance correlation of passivation molecules, it was separately discussed how the functional groups, organic frameworks, and side chains affect the corresponding PV parameters of PSCs. Finally, a guideline was provided for researchers to select more suitable passivation agents, and a perspective was given on future trends in development of passivation strategies.
Here comes the sun: A comprehensive Review on the defect passivation of perovskite solar cells (PSCs) from a molecule design viewpoint is reported. First, the influence of defects on the photovoltaic parameters of PSCs is demonstrated. Then, the structure‐performance correlation of the passivation molecule is investigated. Finally, a perspective on future trends of passivation strategies is provided.
Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is the most important limiting factor for treatment efficiency in EGFR-mutant non-small cell lung cancer ...(NSCLC). Much work has linked the epithelial–mesenchymal transition (EMT) to the emergence of drug resistance, consequently, ongoing research has been focused on exploring the therapeutic options to reverse EMT for delaying or preventing drug resistance. Polyphyllin I (PPI) is a natural compound isolated from Paris polyphylla rhizomes and displayed anti-cancer properties. In the current work, we aimed to testify whether PPI could reverse EMT and overcome acquired EGFR-TKI resistance. We exposed HCC827 lung adenocarcinoma cells to erlotinib which resulted in acquired resistance with strong features of EMT. PPI effectively restored drug sensitivity of cells that obtained acquired resistance. PPI reversed EMT and decreased interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling pathway activation in erlotinib-resistant cells. Moreover, addition of IL-6 partially abolished the sensitization response of PPI. Furthermore, co-treatment of erlotinib and PPI completed abrogation of tumor growth in xenografts, which was associated with EMT reversal. In conclusion, PPI serves as a novel solution to conquer the EGFR-TKI resistance of NSCLC via reversing EMT by modulating IL-6/STAT3 signaling pathway. Combined PPI and erlotinib treatment provides a promising future for lung cancer patients to strengthen drug response and prolong survival.
Subduction transfers surface carbon into the Earth’s interior in a main form of carbonates that influences the global carbon cycles and surface climate through geologic time. Nevertheless, whether ...the fate of downgoing carbonates significantly varies in past subduction zones is rarely constrained by natural observations. Marine carbonates have remarkably higher zinc isotopic ratios (expressed as δ66ZnJMC-Lyon) relative to the mantle (0.99 ± 0.24‰ vs. 0.18 ± 0.05‰), making zinc isotopes a sensitive tracer for subducting carbonates. Here we examine this issue through a comparative zinc isotope study on basalts across the North-South Gravity Lineament (NSGL) in East Asia that were genetically related to two different oceanic slabs. Together with existing data, we show that all basalts in the east of the NSGL have high δ66Zn (∼0.3–0.6‰; n = 134) that do not vary with distances to the trench and are spatially coupled with the horizontally stagnated slab in the transition zone (410–660 km). This indicates that subducting carbonates survived shallow dissolution and were deeply buried during westward subduction of the Paleo-Pacific slab. By contrast, basalts in the west of the NSGL display a gradual decline of δ66Zn from 0.50 ± 0.04‰ to 0.28 ± 0.03‰ (n = 35) with increasing distances to the trench. No known magmatic processes (e.g., partial melting, crystal-melt differentiation, melt-peridotite interaction, and degassing) can account for the spatial Zn isotopic variation. The role of slab-derived sulfate rich fluids is also excluded because of the mantle-like Cu isotopic compositions of these basalts. Instead, the gradual decrease of δ66Zn, together with the coupled decline of CaO/Al2O3, are best explained as the diminished amounts of dissolved carbonates in their mantle sources. Thus, substantial carbonate dissolution must have occurred during southeastward subduction of the Paleo-Asian slab, which prevents deep burial of subducting carbon. The main differences between the two large slabs include: (i) the Paleo-Asian slab has an extended longevity (∼1.1 Ga) and slow spreading rate in comparison with the Paleo-Pacific slab, leading to the main incorporation of carbonate minerals into the altered oceanic crust, and (ii) the younger Paleo-Pacific slab contains abundant deep-sea Mg-rich carbonates that were not sufficiently dissolved at shallow depths. These differences demonstrate that subduction of different oceanic slabs can lead to contrasting fates of subducting carbon in ancient subduction zones, depending on the contents and species of carbonate sediments in the oceanic crust.
Cathodes of lithium-rich layered oxides for high-energy Li-ion batteries in electrically powered vehicles are attracting considerable attention by the research community. However, current research is ...insufficient to account for their complex reaction mechanism and application. Here, the structural evolution of lithium–manganese-rich layered oxides at different temperatures during electrochemical cycling has been investigated thoroughly, and their structural stability has been designed. The results indicated structure conversion from the two structures into a core–shell structure with a single distorted-monoclinic LiTMO2 structure core and disordered-spinel/rock salt structure shell, along with lattice oxygen extraction and lattice densification, transition- metal migration, and aggregation on the crystal surface. The structural conversion behavior was found to be seriously temperature sensitive, accelerated with higher temperature, and can be effectively adjusted by structural design. This study clarifies the structural evolution mechanism of these lithium-rich layered oxides and opens the door to the design of similar high-energy materials with better cycle stability.
Monitoring clinical biomarkers, such as testosterone in serum, is important for disease assessment. Due to the very low concentration of testosterone in serum, we have developed a new strategy for ...its enrichment in serum samples by magnetic molecularly imprinted polymers (MMIPs) technology and detection by nano-electrospray ionization mass spectrometry (Nano-ESI-MS). Testosterone was selectively extracted and enriched by the imprinted polymers on the surface of magnetic particles and the complex matrix was eliminated from the serum. The linear calibration curve was in the range of 0.1–10 μg/L and the limit of detection was 11.4 ng/L. The recovery and repeatability of the spiked serum were satisfactory. These results demonstrate that the proposed method is a promising approach for quantitative analysis of testosterone in serum.
Display omitted
•Synthesis of the MMIPs.•MMIPs in DSPE for serum sample pretreatment.•Analysis of testosterone by DSPE-Nano-ESI-MS.