It is of the utmost importance to promote the charge transport and retard the heterojunction barrier in the functional layers and at their adjacent interfaces to pursuit excellent photovoltaic characteristics of the p...
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It is of the utmost importance to promote the charge transport and retard the heterojunction barrier in the functional layers and at their adjacent interfaces to pursuit excellent photovoltaic characteristics of the perovskite solar cells(PSCs). Here, roomtemperature sputtered-SnO_(2) films are introduced to modify FTO anode for improving carrier extraction and aligning energy band in the TiO_(2)-based planar PSCs. For the SnO_(2)-modified substrate with suitable sputtering duration, the following TiO_(2) film exhibits smoother surface roughness, less surface defects, and lower the trap-assisted interfacial recombination than that directly on the FTO, further facilitating the growth of perovskite grain size and promoting the extraction efficiency of charge carriers. On the basis of the optimized SnO_(2)(6 nm)/TiO_(2) stack layer as electron transport layer(ETL), the PSC exhibits an outstanding power conversion efficiency of 21.45%, which is much better than that of the single TiO_(2)-based device(19.68%). More importantly, the cell with the bilayer ETL shows a long-term stability against air, maintaining over 76% of its initial efficiency after 40 d. These achievements suggest that this study provides a feasible path to design energy level alignment and low temperature ETL for highly efficient and stable PSCs.
Aluminum coating is a potential candidate for cadmium coating replacement due to its excellent corrosion resistance and nontoxicity. Among the fabrication methods of Al coating, plating Al via ionic liquids has drawn ...
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T-shaped joints of high-strength aluminum alloy welded by friction stir welding (FSW) are expected to replace the traditional riveting structures. However, the corrosion of T-joint still hinder the popularization of F...
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Exploring halogen engineering is of great significance for reducing the density of defect states in crystals of organic-inorganic hybrid perovskites and hence improving the crystal ***,high-quality single crystals of ...
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Exploring halogen engineering is of great significance for reducing the density of defect states in crystals of organic-inorganic hybrid perovskites and hence improving the crystal ***,high-quality single crystals of PEA_(2)PbI_(4)(X=CI,Br,I)and their para-F(p-F)substitution analogs are prepared using the facile solution method to study the effects of both p-F substitution and halogen anion *** p-F substitution,the triclinic PEA_(2)PbX_(4)(X=Cl,Br)and cubic PEA_(2)PbX_(4)(X=I)crystals unifies to monoclinic crystal structure for p-F-PEA_(2)PbX_(4)(X=Cl,Br,I)*** p-F substitution and halogen engineering,together with crystal structure variation,enable the tunability of optoelectrical ***,after the p-F substitution,the energy levels are lowered with increased Fermi levels,and the bandgaps of p-F-PEA_(2)PbX_(4)(X=Cl,Br,I)are slightly *** from the enhancement of the charge transfer and the reduced trap density by p-F substitution and halogen anion engineering,the average carrier lifetime of the p-F-PEA_(2)PbI_(4)is obviously *** with PEA_(2)PbI_(4)the X-ray detector based on p-F-PEA_(2)PbI_(4)single crystals exhibits higher radiation stability under high-dose X-ray irradiation,implying long-term operando stability.
In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluat...
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In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluation of the energy storage capability of a *** this work,high recyclable energy density and responsivity,i.e.,W_(rec)=161.1 J·cm^(-3) and ξ=373.8 J·(kV·m^(2))^(-1),have been simultaneously achieved in a prototype perovskite dielectric,BaTiO_(3),which is integrated on Si at 500℃ in the form of a submicron thick *** ferroelectric film features a multi-scale polar structure consisting of ferroelectric grains with different orientations and inner-grain ferroelastic domains.A LaNiO_(3) buffer layer is used to induce a{001}textured,columnar nanograin microstructure,while an elevated deposition temperature promotes lateral growth of the nanograins(in-plane diameter increases from~10-20 nm at lower temperatures to~30 nm).These preferably oriented and periodically regulated nanograins have resulted in a small remnant polarization and a delayed polarization saturation in the film’s P-E behavior,leading to a high recyclable energy ***,an improved polarizability/dielectric constant of the BaTiO_(3) film has produced a much larger maximum polarization than those deposited at lower temperatures at the same electric field,leading to a record-breaking responsivity for this simple perovskite.
作者:
Xiaoping SuZhao WangNing LiLongjian LiPing ZhangMing SunXiaoxun MaSchool of Chemical Engineering
Northwest Minzu UniversityKey Laboratory of Environment-Friendly Composites of the State Ethnic Affairs CommissionGansu Provincial Biomass Function Composites Engineering Research CenterKey Laboratory for Utility of Environment-Friendly Composites and Biomass in Universities of Gansu ProvinceGansu Province Research Center for Basic Sciences of Surface and Interface ChemistryLanzhou 730030China School of Chemical Engineering
Northwest UniversityInternational Science&Technology Cooperation Base of MOST for Clean Utilization of Hydrocarbon ResourcesChemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyShaanxi Research Center of Engineering Technology for Clean Coal ConversionCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiXi'an 710069China
The pyrolysis process of Shendong coal(SD)was first studied by combining the characteristics of thermal gravimetric(TG),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and Gray-King assay(GK).The results show ...
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The pyrolysis process of Shendong coal(SD)was first studied by combining the characteristics of thermal gravimetric(TG),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and Gray-King assay(GK).The results show that the order of coke yields is G-K(76.35%(mass))>TG(73.11%(mass))>Py(70.03%(mass)).G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08%(mass)and 3.24%(mass),*** with slow pyrolysis,fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds,mono-ring aromatics and ***,the content of phenolics increases significantly from 15.49%to 35.17%,but the content of multi-ring aromatics decreases from 23.13%to 2.36%.By comparing the compositions of Py primary tar and G-K final tar,it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters,condensation of mono-ring aromatics with low carbon alkene,ring opening,isomerization of tri-ring aromatics,hydrogenation of aromatics and acids.
作者:
Xiaoping SuNing LiLongjian LiReyila TuerhongYongchong YuPing ZhangQiong SuTao ShenMing SunXiaoxun MaKey Laboratory of Environment-Friendly Composite Materials of the State Ethnic Affairs Commission
Gansu Provincial Biomass Function Composites Engineering Research CenterKey Laboratory for Utility of Environment-Friendly Composite Materials and Biomass in University of Gansu ProvinceGansu Province Research Center for Basic Sciences of Surface and Interface ChemistryCollege of Chemical EngineeringNorthwest Minzu UniversityLanzhou 730124China School of Chemical Engineering
Northwest UniversityInternational Science&Technology Cooperation Base of MOST for Clean Utilization of Hydrocarbon ResourcesChemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyShaanxi Research Center of Engineering Technology for Clean Coal ConversionCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiXi'an 710069China
Coal has a highly complex chemical structure,similar to polymers,coal is a macromolecular structure composed of a large number of“similar compounds”,which is called the basic structural *** coal structure is the bas...
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Coal has a highly complex chemical structure,similar to polymers,coal is a macromolecular structure composed of a large number of“similar compounds”,which is called the basic structural *** coal structure is the basis of its transformation and ***(SD)coal was analyzed by FTIR,XRD,XPS,and *** results show that SD coal normalized structure formula is C_(100)H_(68.5)O_(35.7)N_(1.2)S_(0.2)and the average number of aromatic rings is 1.98.-CH_(2)-content accounts for about 82%in aliphatic CeH region,and the ratio of ether bond CeO,aromatic ether C-O and C=O is about 2:1:11 in oxygen-containing functional group *** d_(002),L_(C),L_(a)and N_(C)of S_(D)coal microcrystalline structure parameters are 0.1832 nm,1.4688 nm,2.0852 nm and 9.017,*** carbon and aliphatic carbon ratios of SD coal are 55.67%and 29.97%,aromatic cluster size and average methylene chain length are 0.224 and *** on these structural parameters,molecular model of SD coal was constructed with^(13)C SSNMR experimental spectra as a *** model was constructed with an atom composition of C_(214)H_(214)O_(49)N_(2)S.
The replacement of small cations with bulkier organic cations containing long alkyl chains or benzene rings to form a thin two-dimensional(2D)perovskite passivation layer on three-dimensional(3D)perovskite(2D/3D)has b...
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The replacement of small cations with bulkier organic cations containing long alkyl chains or benzene rings to form a thin two-dimensional(2D)perovskite passivation layer on three-dimensional(3D)perovskite(2D/3D)has become a promising strategy for improving both the efficiency and stability of perovskite solar cells(PSCs).The 2 D layer defines the interfacial chemistry and physics at the 2D/3D bilayer and endows the 2D/3D structure with better chemical and thermal ***,2D/3D(CF_(3)-PEA)_(2) FA_(0.85)MA_(0.15)Pb_(2)I_(7)/FA_(0.85)MA_(0.15)PbI_(3) planar heterojunction perovskite was produced using a facile interfacial ion exchange *** 2 D(CF_(3)-PEA)_(2) FA_(0.85)MA_(0.15)Pb_(2)I_(7) capping layer can not only passivate the FA_(0.85)MA_(0.15)PbI_(3) film but also act as super-hydrophobic layer to inhibit water diffusion and significantly enhance the *** 2D capping layer can also establish a unique graded band structure at the perovskite/Spiro-OMeTAD interface and lead to p-type doping for Spiro-OMeTAD layer which is beneficial for efficient charge *** PSCs based on this 2D/3D heterojunction yield a champion power conversion efficiency(PCE)of 23.1%and improved *** device maintains 84%output for 2400 h aging under ambient environmental conditions without encapsulation,and maintains 81%for 200 h under illumination with *** work will inspire the design of more fluorinated 2D perovskite interfaces for advanced photovoltaics and beyond.
CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding ***,open-circuit voltage(Voc)loss caused by band mismatch and charge r...
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CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding ***,open-circuit voltage(Voc)loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device ***,we proposed a bilayer electron transport layer ZnO(bottom)/SnO_(2)(top)to reduce the Voc loss(Eloss)and promote device Voc by ZnO insert layer thickness modulation,which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier *** addition,guanidinium iodide top surface treatment is used to further reduce the trap density,stabilize the perovskite film and align the energy levels,which promotes the fill factor,short-circuit current density(Jsc),and stability of the *** a result,the champion cell of double-side optimized CsPbI_(2)Br perovskite solar cells exhibits an extraordinary efficiency of 16.25%with the best Voc as high as 1.27 V and excellent thermal and storage stability.
The hole transport material (HTM) plays an extremely important role to determine the power conversion efficiency (PCE) and the stability of perovskite solar cells (PSCs). Herein, we report an effective strategy to imp...
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The hole transport material (HTM) plays an extremely important role to determine the power conversion efficiency (PCE) and the stability of perovskite solar cells (PSCs). Herein, we report an effective strategy to improve the performance of HTMs by introducing −CF_(3) groups via the rational decorative mode. Upon direct attachment or nonconjugated alkoxyl bridging of −CF_(3) groups on the terminal diphenylamines, the resulting molecular HTMs, i.e., 2,7-BCzA4CF_(3) and 2,7-BCzA4OCCF_(3), show distinct properties. Compared with 2,7-BCzA4CF_(3), the nonconjugated alkoxyl bridging −CF_(3) group-based 2,7-BCzA4OCCF_(3) exhibits better thermal stability, hydrophobicity, and a dramatically upgraded hole mobility by 135.7-fold of magnitude to 1.71 × 10^(−4) cm^(2) V^(−1) S^(−1). The PSCs with 2,7-BCzA4OCCF_(3) as HTM exhibit an PCE of up to 20.53% and excellent long-term stability, maintaining 92.57% of their performance for 30 days in air with humidity of 30% without encapsulation. This work provides beneficial guidelines for the design of new HTMs for efficient and stable PSCs.
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