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Structural changes in basalt sorbents in the course of thermal treatment were studied by complex emanation-thermal analysis. Sorbent was prepared by two-stage treatment of staple basalt fibers with hydrochloric acid. The sorption isotherms of liquid nitrogen vapor on these new sorbents were obtained, the open surface areas were determined, and the porosity and pore size distribution of leached fibers were evaluated. The data of thermostimulated gas liberation method showed that water sorbed on porous basalt fibers occurs in two energy-different states: the main fraction of water is desorbed at 90-110°C, and the remainder, at 300-320°C. The sorbent is completely regenerated on heating to 550°C. Degradation of the fiber pore structure begins at 700°C, and fiber sintering, at temperatures greater than 1150°C. A mathematical model of emanation of the porous systems in the sintering mode was proposed, and the activation energies of emanation of the initial and porous fibers were calculated. It was found that leaching, along with formation and development of the mesopore system, generates numerous point defects. Due to significant sorption activity and high thermal stability, fibrous basalt sorbents can be recommended to prepare sorption filters for treatment of radiochemical production wastes. 相似文献
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Sigalit Aharon Michael Layani Bat‐El Cohen Efrat Shukrun Shlomo Magdassi Lioz Etgar 《Advanced Materials Interfaces》2015,2(12)
This work reports on the preparation of semitransparent perovskite solar cells. The cells transparency is achieved through a unique wet deposition technique that creates perovskite grids with various dimensions. The perovskite grid is deposited on a mesoporous TiO2 layer, followed by hole transport material deposition and evaporation of a semitransparent gold film. Control of the transparency of the solar cells is achieved by changing the perovskite solution concentration and the mesh openings. The semitransparent cells demonstrate 20–70% transparency with a power conversion efficiency of 5% at 20% transparency. This is the first demonstration of the possibility to create a controlled perovskite pattern using a direct mesh‐assisted assembly deposition method for fabrication of a semitransparent perovskite‐based solar cell. 相似文献
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Daniel B. Straus Shu Guo AM Milinda Abeykoon Robert J. Cava 《Advanced materials (Deerfield Beach, Fla.)》2020,32(32):2001069
Despite the tremendous interest in halide perovskite solar cells, the structural reasons that cause the all-inorganic perovskite CsPbI3 to be unstable at room temperature remain mysterious, especially since many tolerance-factor-based approaches predict CsPbI3 should be stable as a perovskite. Here single-crystal X-ray diffraction and X-ray pair distribution function (PDF) measurements characterize bulk perovskite CsPbI3 from 100 to 295 K to elucidate its thermodynamic instability. While Cs occupies a single site from 100 to 150 K, it splits between two sites from 175 to 295 K with the second site having a lower effective coordination number, which, along with other structural parameters, suggests that Cs rattles in its coordination polyhedron. PDF measurements reveal that on the length scale of the unit cell, the Pb I octahedra concurrently become greatly distorted, with one of the I Pb I angles approaching 82° compared to the ideal 90°. The rattling of Cs, low number of Cs I contacts, and high degree of octahedral distortion cause the instability of perovskite-phase CsPbI3. These results reveal the limitations of tolerance factors in predicting perovskite stability and provide detailed structural information that suggests methods to engineer stable CsPbI3-based solar cells. 相似文献
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Maciej Klein Yutao Wang Jingyi Tian Son Tung Ha Ramón Paniagua-Domínguez Arseniy I. Kuznetsov Giorgio Adamo Cesare Soci 《Advanced materials (Deerfield Beach, Fla.)》2023,35(1):2207317
Emerging immersive visual communication technologies require light sources with complex functionality for dynamic control of polarization, directivity, wavefront, spectrum, and intensity of light. Currently, this is mostly achieved by free space bulk optic elements, limiting the adoption of these technologies. Flat optics based on artificially structured metasurfaces that operate at the sub-wavelength scale are a viable solution, however, their integration into electrically driven devices remains challenging. Here, a radically new approach to monolithic integration of a dielectric metasurface into a perovskite light-emitting transistor is demonstrated. It is shown that nanogratings directly structured on top of the transistor channel yield an 8-fold increase of electroluminescence intensity and dynamic tunability of polarization. This new light-emitting metatransistor device concept opens unlimited opportunities for light management strategies based on metasurface design and integration. 相似文献
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Jianan Chen Zhaobing Tang Yangzhou Zhou Shuo Ding Liang Li Lei Qian Chaoyu Xiang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(19):2207520
Formamidine lead iodide (FAPbI3) is an important material for realizing high-performance near-infrared light-emitting diodes (NIR-LEDs). However, due to the uncontrollable growth of solution-processed films which usually causes low coverage, and poor surface morphology, the development of FAPbI3-based NIR-LEDs is hindered, restraining its potential industrial applications. In this work, by employing glutamine (Gln) in perovskite precursor, the quality of FAPbI3 film is improved significantly. Due to the ameliorated solution process by the organic additive, the film coverage over the substrate is substantially enhanced. Meanwhile, the trap state of grain is largely reduced. Consequently, NIR perovskite LEDs are demonstrated with a maximum external quantum efficiency (EQE) of 15% with the emission peak at 795 nm, which is four times higher than the device with pristine perovskite film. 相似文献
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Yanbo Wang Xiao Liu Zhongmin Zhou Pengbin Ru Han Chen Xudong Yang Liyuan Han 《Advanced materials (Deerfield Beach, Fla.)》2019,31(47)
Perovskite solar cells (PSCs) have undergone an incredibly fast development and attracted intense attention worldwide owing to their high efficiency and low‐cost fabrication. However, it is challenging to make a reliable measurement of PSCs, which creates great difficulty for researchers to compare and reproduce published results. Herein, the major measurement methods and key factors affecting evaluation of PSCs are summarized, such as hysteresis in current–voltage measurement, calibration of solar simulators for less mismatch in spectra and light intensity, and the area for the calculation of current density and power conversion efficiency. PSCs are also compared with n–i–p or p–i–n structures that exhibit different feedback under the same measurement methods. Finally, a measurement proposal is provided to help researchers obtain reliable measurement results close to those certified by public test centers. 相似文献
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Solvent extraction of Th from aqueous chloride solutions with the ThO2 content below 1 g l?1 obtained in processing perovskite was studied. Di(2-ethylhexyl) hydrogen phosphate, octanol, and tributyl phosphate were tested as extractants. Thorium is extracted most efficiently and selectively from concentrated aqueous CaCl2 with tributyl phosphate. The conditions for preparing solid concentrate containing about 20 wt % Th were found. 相似文献
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钙钛矿锰氧化物(Perovskite manganese oxide, PMO)因受外界条件激励而发生变色的特性, 在散热领域中受到广泛关注。目前绝大多数针对PMO的变色特性的研究都是以温度激励为基础, 以电场激励实现的散热器件仍旧缺乏。由于电场激励伴随着焦耳热的影响, 目前PMO材料是否存在电致变色性能尚未得到明确证明。针对以上问题, 本研究利用电场激励对PMO内部Mn元素的影响, 提出了一种针对PMO材料的电改性方法。通过电改性大幅减弱PMO热致变色性能, 进而使La0.7Ca0.25K0.05MnO3(LCKMO)在电场激励实验中能够排除焦耳热的影响。对LCKMO电改性前后的热致变色及电致变色性能进行研究。电改性前的LCKMO发射率随温度升高而增大, 最大增量为17%。并且在受21 V电场激励后, 其发射率在173、203、243、273和373 K分别出现了15%、16%、10%、0.6%和1.4%的增量。电改性后的LCKMO热致变色性能大幅减弱, 且在受21 V电场激励后, 其发射率在273和373 K出现了10.7%和9.3%的增量。电改性前后的实验结果表明: LCKMO存在电致变色性能, 并且电场激励对LCKMO发射率的调控机制存在明显规律。此外, 针对PMO材料的电改性方法不仅能令PMO材料在排除焦耳热的影响下进行电致变色研究, 更为调控PMO材料热致变色性能提供了新的可能。 相似文献
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Sang-Won Lee Soohyun Bae Donghwan Kim Hae-Seok Lee 《Advanced materials (Deerfield Beach, Fla.)》2020,32(51):2002202
The status and problems of upscaling research on perovskite solar cells, which must be addressed for commercialization efforts to be successful, are investigated. An 804 cm2 perovskite solar module has been reported with 17.9% efficiency, which is significantly lower than the champion perovskite solar cell efficiency of 25.2% reported for a 0.09 cm2 aperture area. For the realization of upscaling high-quality perovskite solar cells, the upscaling and development history of conventional silicon, copper indium gallium sulfur/selenide and CdTe solar cells, which are already commercialized with modules of sizes up to ≈25 000 cm2, are reviewed. GaAs, organic, dye-sensitized solar cells and perovskite/silicon tandem solar cells are also reviewed. The similarities of the operating mechanisms between the various solar cells and the origin of different development pathway are investigated, and the ideal upscaling direction of perovskite solar cells is subsequently proposed. It is believed that lessons learned from the historical analysis of various solar cells provide a fundamental diagnosis of relative and absolute development status of perovskite solar cells. The unique perspective proposed here can pave the way toward the upscaling of perovskite solar cells. 相似文献
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钙钛矿太阳能电池自2009年被提出以来取得了迅速的发展,其性能已超过了多晶硅太阳能电池。目前,钙钛矿太阳能电池的光电转换效率已达到20.8%。但是它面临着稳定性差的问题,这严重阻碍了其商业化进程。本文将总结近年来钙钛矿太阳能电池取得的部分研究进展和存在的问题,讨论提高钙钛矿太阳能电池光电转换效率和稳定性的途径,并对未来发展的方向进行了展望。 相似文献
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Jiangjian Shi Xin Xu Dongmei Li Qingbo Meng 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(21):2472-2486
The interfacial atomic and electronic structures, charge transfer processes, and interface engineering in perovskite solar cells are discussed in this review. An effective heterojunction is found to exist at the window/perovskite absorber interface, contributing to the relatively fast extraction of free electrons. Moreover, the high photovoltage in this cell can be attributed to slow interfacial charge recombination due to the outstanding material and interfacial electronic properties. However, some fundamental questions including the interfacial atomic and electronic structures and the interface stability need to be further clarified. Designing and engineering the interfaces are also important for the next‐stage development of this cell. 相似文献
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J. Guimpel N. Haberkorn M. Sirena L. B. Steren W. Saldarriaga E. Baca M. E. Gómez 《Journal of Low Temperature Physics》2004,135(1-2):115-118
The effect of interface disorder in perovskite superlattices, either with the substrate or between layers dominates the physics of the material, even when the lattice parameter of the component materials differs in less than 1%. Unexpected behavior emerges, like exchange bias in a system where no antiferromagnetic material has been included in the superlattice design. 相似文献