- 标题
- 摘要
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- 实验方案
- 产品
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Rooma??Temperature Partial Conversion of ?±a??FAPbI <sub/>3</sub> Perovskite Phase via PbI <sub/>2</sub> Solvation Enables Higha??Performance Solar Cells
摘要： The two-step conversion process consisting of metal halide deposition followed by conversion to hybrid perovskite has been successfully applied toward producing high-quality solar cells of the archetypal MAPbI3 hybrid perovskite, but the conversion of other halide perovskites, such as the lower bandgap FAPbI3, is more challenging and tends to be hampered by the formation of hexagonal nonperovskite polymorph of FAPbI3, requiring Cs addition and/or extensive thermal annealing. Here, an efficient room-temperature conversion route of PbI2 into the α-FAPbI3 perovskite phase without the use of cesium is demonstrated. Using in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and quartz crystal microbalance with dissipation (QCM-D), the conversion behaviors of the PbI2 precursor from its different states are compared. α-FAPbI3 forms spontaneously and efficiently at room temperature from P2 (ordered solvated polymorphs with DMF) without hexagonal phase formation and leads to complete conversion after thermal annealing. The average power conversion efficiency (PCE) of the fabricated solar cells is greatly improved from 16.0(±0.32)% (conversion from annealed PbI2) to 17.23(±0.28)% (from solvated PbI2) with a champion device PCE > 18% due to reduction of carrier recombination rate. This work provides new design rules toward the room-temperature phase transformation and processing of hybrid perovskite films based on FA+ cation without the need for Cs+ or mixed halide formulation.
关键词： FAPbI3,two-step conversion,high performance,hybrid perovskite solar cells,quartz-crystal microbalance,in situ grazing incidence wide angle x-ray scattering
更新于2025-09-16 10:30:52
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Machine learning–assisted molecular design and efficiency prediction for high-performance organic photovoltaic materials
摘要： In the process of finding high-performance materials for organic photovoltaics (OPVs), it is meaningful if one can establish the relationship between chemical structures and photovoltaic properties even before synthesizing them. Here, we first establish a database containing over 1700 donor materials reported in the literature. Through supervised learning, our machine learning (ML) models can build up the structure-property relationship and, thus, implement fast screening of OPV materials. We explore several expressions for molecule structures, i.e., images, ASCII strings, descriptors, and fingerprints, as inputs for various ML algorithms. It is found that fingerprints with length over 1000 bits can obtain high prediction accuracy. The reliability of our approach is further verified by screening 10 newly designed donor materials. Good consistency between model predictions and experimental outcomes is obtained. The result indicates that ML is a powerful tool to prescreen new OPV materials, thus accelerating the development of the OPV field.
关键词： organic photovoltaics,molecular design,machine learning,high-performance materials,efficiency prediction
更新于2025-09-12 10:27:22
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Polarization induced two-dimensional electron gas in ZnO/ZnMgO Heterointerface for High-performance enhanced UV photodetector
摘要： The spontaneous formation of two-dimensional electron gas (2DEG) with a high carrier density (~1018 cm-3) was achieved at a ZnO/Mg0.2Zn0.8O interface grown using a facile radio-frequency magnetron sputtering system on a quartz substrate. Compared with Mg0.2Zn0.8O ultraviolet (UV) photodetectors (PDs) with and without a ZnO buffer layer, the PD based on ZnO/Mg0.2Zn0.8O bilayer films exhibited not only sensitivity to dual wavelength in the UV region, but also significantly enhanced spectral responsivity, photocurrent-to-dark current ratio (107), specific detectivity (1014), and UV/visible rejection ratio of about four orders of magnitude at a low operating voltage bias. Induced by 2DEG, the external quantum efficiency (EQE) of photodetector reached 14858% at 10 V, indicating that a considered high gain was achieved in the device based on this heterojunction architecture. The gain mechanism was further demonstrated by polarization induction and band bending in detail. This application of 2DEG in a practical detector offers a novel and effective approach for the substantial improvement in the high-performance of ZnO/Mg0.2Zn0.8O dual-band UV PDs.
关键词： two-dimensional electron gas,polarization,high-performance UV PDs,ZnO/Mg0.2Zn0.8O heterointerface,gain
更新于2025-09-12 10:27:22
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Strontium Chloride Passivated Perovskite Thin Films for Efficient Solar Cells with Power Conversion Efficiency over 21% and Superior Stability
摘要： Industrialization of perovskite solar cells (PSCs) is constrained by adverse stability in the air. Herein, we report an effective strontium chloride (SrCl2) passivation upon the HC(NH2)2-CH3NH3 (FA-MA) based perovskite thin films for the suppression of non-radiative recombination. Moreover, the recombination dynamics, crystallinity, carrier transport, morphology and the elemental stoichiometry of this film were systematically studied. By optimizing the concentration of SrCl2, the corresponding devices exhibited an increased open-circuit voltage (1.00 V vs 1.09 V), in consistent with the enhanced photoluminescence lifetime. The champion passivated device showed a ascendant power conversion efficiency (PCE) about 21.11% , with over 90% retention of the primal PCE in dry air after 1000 h aging with 20% ~ 30% humidity. A superior stability and an accelerated eletron/hole extraction ability were futher observed by time-resolved photoluminescence (TRPL) spectroscopy.
关键词： Charge-transport,High-performance,Spin coating,Crystallzation,Hysteresis,Ion migration
更新于2025-09-12 10:27:22
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Red‐Blood‐Cell Waveguide as a Living Biosensor and Micromotor
摘要： The changes of flavor components during boiling in Lentinus edodes were studied by high-performance liquid chromatography and gas chromatography-mass spectrometry in this article. Results showed that nonvolatile flavor components in L. edodes gradually transferred into the soup during boiling. Contents of nonvolatile flavor substances in the soup increased significantly (p < .05) compared with the preboiling period (15 minutes) and gradually maintained a balanced situation with the boiling time extended. During boiling, content of alcohols gradually reduced, especially the content of 1-octen-3-ol, which is a typical flavor component in L. edoedes. The contents of sulfur compounds, aldehydes, and hydrocarbons increased first and finally decreased gradually with the boiling time extended. Therefore, the changes of flavor components in the soup almost maintained a balanced situation with the boiling time from 30 to 60 minutes. The results of this article could provide a theoretical basis for the changes of flavor compounds in L. edodes during boiling.
关键词： flavor components,gas chromatography–mass spectrometry,High-performance liquid chromatography,boiling,Lentinus edodes
更新于2025-09-11 14:15:04
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Controlling Surface Chemical Heterogeneities of Ultrasmall Fluorescent Core–Shell Silica Nanoparticles as Revealed by High-Performance Liquid Chromatography
摘要： Ultrasmall (diameter below 10 nm) fluorescent core?shell silica nanoparticles have garnered increasing attention in recent years as a result of their high brightness and favorable biodistribution properties important for applications including bioimaging and nanomedicine. Here, we present an in-depth study that provides new insights into the physical parameters that govern full covalent fluorescent dye encapsulation within the silica core of poly(ethylene glycol)-coated core?shell silica nanoparticles referred to as Cornell prime dots (C′ dots). We use a combination of high-performance liquid chromatography (HPLC), gel-permeation chromatography, and fluorescence correlation spectroscopy to monitor the result of ammonia concentration in the synthesis of C′ dots from negatively and positively charged versions of near-infrared dyes Cy5 and Cy5.5. HPLC, in particular, allows the distinction between cases of full versus partial dye encapsulation in the silica particle core leading to surface chemical heterogeneities in the form of hydrophobic surface patches, which, in turn, modulate biological response in ferroptotic cell death experiments. Our results demonstrate that there is a complex interplay between dye?dye and dye?silica cluster interactions originally formed in the sol?gel synthesis governing optimal dye encapsulation. We expect that the reduced surface chemical heterogeneities will make the resulting nanoparticles attractive for a number of applications in biology and medicine.
关键词： gel-permeation chromatography,ferroptotic cell death,high-performance liquid chromatography,fluorescent core?shell silica nanoparticles,fluorescence correlation spectroscopy
更新于2025-09-11 14:15:04
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Interface engineering gifts CsPbI2.25Br0.75 solar cells high performance
摘要： Organic-inorganic halide perovskite (ABX3) solar cells (PSCs) have made great progress in recent years [1]. The power conversion efficiency (PCE) has increased up to 25.2% (NREL Best Research-Cell Efficiency Chart, https://www.nrel.gov/pv/cell-efficiency.html, Accessed August 2019). However, they suffer from poor thermal stability due to the volatile A-site organic cations. All-inorganic CsPbI3–xBrx perovskite materials can tolerate temperature exceeding 400 °C, while organic–inorganic halide PSCs rapidly deteriorated at greater than 200 °C [2]. The excellent thermal stability of inorganic perovskites makes them promising materials for PSCs [3]. Their relatively low PCE is due to two reasons. One is the wide bandgap, which leads to insufficient light absorption and low Jsc. Developing tandem solar cells is an effective approach to absorb sunlight as much as possible [4]. Another is the large energy loss (Eloss), leaving much room for increasing Voc. Interface engineering can reduce the Eloss and increase the PCE. Wang et al. [5] reported a 17.06% PCE by using PTABr-treated CsPbI3 as the absorber. The post-treatment with PTABr can realize gradient Br-doping and surface passivation, leading to enhanced Voc and FF. They also modified CsPbI3 surface with choline iodine (CHI), which increased the charge-carrier lifetime and improved the energy level alignment between CsPbI3 and charge-transport layers. CHI-CsPbI3 solar cells gave a PCE of 18.4% [6]. Besides, choosing electron-transport layers (ETLs) and hole-transport layers (HTLs) with suitable energy levels is also effective for improving Voc [7]. In our previous work, we applied DPPA-modified ZnO as ETL for CsPbI2.25Br0.75 solar cells, obtaining a 15.98% PCE with an enhanced Voc [8]. Yan et al. [9] used SnO2/ZnO bilayer as ETL to get high Voc. They also used PN4N-modified SnO2 as ETL and PDCBT as HTL in CsPbI2Br solar cells, obtaining a 16.2% PCE with a 1.30 V Voc [10]. In this work, we made inorganic PSCs with a structure of ITO/SnO2/ZnO/CsPbI2.25Br0.75/HTL/MoO3/Ag (Fig. 1a). PTAA doped with polymer donor PBD2T [11] was used as HTL (D-PTAA). The deep highest occupied molecular orbital (HOMO) level of PBD2T matches HOMO of CsPbI2.25Br0.75 well. Meanwhile, PBD2T can passivate the trap states on perovskite surface and suppress interfacial charge recombination. The solar cells with D-PTAA delivered a 17.37% PCE, which is the highest efficiency for Br-doped inorganic PSCs.
关键词： High performance,Solar cells,CsPbI2.25Br0.75,Interface engineering
更新于2025-09-11 14:15:04
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Aggregation-Induced Delayed Fluorescence Luminogens with Accelerated Reverse Intersystem Crossing for High-Performance OLEDs
摘要： A fast reverse intersystem crossing (RISC) is of high importance for delayed fluorescence emitters in terms of increasing exciton utilization and suppressing efficiency roll-off. Herein, new robust luminogens comprised of carbonyl, phenoxazine and chlorine-substituted carbazole derivatives are synthesized and characterized. They own distinct aggregation-induced delayed fluorescence (AIDF) feature, and exhibit high photoluminescence efficiencies and short delayed fluorescence lifetimes in neat films. The RISC is conspicuously accelerated owing to their tiny singlet-triplet energy splitting and greatly enhanced spin-orbit coupling by heavy atom effect in neat films. They can function efficiently as light-emitting layers in nondoped OLEDs, providing excellent maximum electroluminescence (EL) efficiencies of 20.4–21.7%, and can also perform outstandingly in doped OLEDs in a wide doping concentration range (5–90 wt%), affording impressive EL efficiencies of up to 100.1 cd A–1, 104.8 lm W–1 and 29.1%, with small efficiency roll-off. These findings demonstrate the AIDF luminogens with fast RISC are promising candidates to fulfill various demands of production and application of OLEDs.
关键词： OLEDs,Reverse Intersystem Crossing,Luminogens,Aggregation-Induced Delayed Fluorescence,High-Performance
更新于2025-09-11 14:15:04
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Enhanced Synergetic Catalytic Effect of Mo <sub/>2</sub> C/NCNTs@Co Heterostructures in Dye-Sensitized Solar Cells: Fine-Tuned Energy Level Alignment and Efficient Charge Transfer Behavior
摘要： This study proposed a new ballpoint connector-protected salt-oil-salt liquid phase microextraction for extraction and enrichment of trace rhein and chrysophanol in rhubarb prior to determination of the analytes by high performance liquid chromatography. In this study, a handy ballpoint connector (between ballpoint tip and ink chamber) was used as extraction device, in which its cavity was filled with n-octanol, and the bare n-octanol in its two opening ends was covered with a thin layer of sodium chloride film. The design subtly assembled salt film onto ballpoint connector for extraction and enrichment, which greatly improved the enrichment factors of the target analytes. Moreover, the novel procedure and its extraction mechanism were described and analyzed, and several crucial parameters reflecting the extraction effect were investigated and optimized. Under optimum conditions, high enrichment factors (247 and 127), good linearities with r ≥ 0.9998, limits of detection (0.6–1.1 ng/mL), relative standard deviations of intra- and interday (2.2–8.8% and 4.3–8.9%), and average recoveries (97.6–98.1%), were obtained, respectively. The proposed method can not only eliminate the negative effects from viscosity and ion strength at high salt concentration of sample phase, but also make salting-out effect be focused on small area so as to maximize the extraction effect.
关键词： high-performance liquid chromatography,rhubarb,liquid-phase microextraction,ballpoint connector,Traditional Chinese medicine
更新于2025-09-11 14:15:04
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7.3: Research on LCD display performance improvement based on mini‐LED backlight
摘要： The changes of flavor components during boiling in Lentinus edodes were studied by high-performance liquid chromatography and gas chromatography-mass spectrometry in this article. Results showed that nonvolatile flavor components in L. edodes gradually transferred into the soup during boiling. Contents of nonvolatile flavor substances in the soup increased significantly (p < .05) compared with the preboiling period (15 minutes) and gradually maintained a balanced situation with the boiling time extended. During boiling, content of alcohols gradually reduced, especially the content of 1-octen-3-ol, which is a typical flavor component in L. edoedes. The contents of sulfur compounds, aldehydes, and hydrocarbons increased first and finally decreased gradually with the boiling time extended. Therefore, the changes of flavor components in the soup almost maintained a balanced situation with the boiling time from 30 to 60 minutes. The results of this article could provide a theoretical basis for the changes of flavor compounds in L. edodes during boiling.
关键词： flavor components,gas chromatography–mass spectrometry,High-performance liquid chromatography,boiling,Lentinus edodes
更新于2025-09-11 14:15:04