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Dr. Xuesong Yin Dr. Chunhua Tang Dr. Guojun Qi Prof. Hao Gong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(6):2146-2152
The synthesis of previously unknown perovskite (CH3NH3)2PdCl4 is reported. Despite using an organic cation with the smallest possible alkyl group, a 2D organic–inorganic layered Pd‐based perovskites was still formed. This demonstrates that Pd‐based 2D perovskites can be obtained even if the size of the organic cation is below the size limit predicted by the Goldschmidt tolerance‐factor formula. The (CH3NH3)2PdCl4 phase has a bulk resistivity of 1.4 Ω cm, a direct optical gap of 2.22 eV, and an absorption coefficient on the order of 104 cm?1. XRD measurements suggest that the compound is moderately stable in air, an important advantage over several existing organic–inorganic perovskites that are prone to phase degradation problems when exposed to the atmosphere. Given the recent interest in organic–inorganic perovskites, the synthesis of this new Pd‐based organic–inorganic perovskite may be helpful in the preparation and understanding of other organic–inorganic perovskites. 相似文献
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Jiangjian Shi Huiyun Wei Songtao Lv Xin Xu Huijue Wu Prof. Yanhong Luo Prof. Dongmei Li Prof. Qingbo Meng 《Chemphyschem》2015,16(4):842-847
Carrier density and transport properties in the CH3NH3PbI3 thin film have been investigated. It is found that the carrier density, the depletion field, and the charge collection and transport properties in the CH3NH3PbI3 absorber film can be controlled effectively by different concentrations of reactants. That is, the carrier properties and the self‐doping characteristics in CH3NH3PbI3 films are strongly influenced by the reaction thermodynamic and kinetic processes. Furthermore, by employing mixed solvents with ethanol and isopropanol to deposit the CH3NH3PbI3 film, the charge collection and transport efficiencies are improved significantly, thereby yielding an overall enhanced cell performance. 相似文献
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Methylamine‐Gas‐Induced Defect‐Healing Behavior of CH3NH3PbI3 Thin Films for Perovskite Solar Cells 下载免费PDF全文
Dr. Zhongmin Zhou Zaiwei Wang Yuanyuan Zhou Dr. Shuping Pang Dong Wang Dr. Hongxia Xu Dr. Zhihong Liu Prof. Nitin P. Padture Dr. Guanglei Cui 《Angewandte Chemie (International ed. in English)》2015,54(33):9705-9709
We report herein the discovery of methylamine (CH3NH2) induced defect‐healing (MIDH) of CH3NH3PbI3 perovskite thin films based on their ultrafast (seconds), reversible chemical reaction with CH3NH2 gas at room temperature. The key to this healing behavior is the formation and spreading of an intermediate CH3NH3PbI3?xCH3NH2 liquid phase during this unusual perovskite–gas interaction. We demonstrate the versatility and scalability of the MIDH process, and show dramatic enhancement in the performance of perovskite solar cells (PSCs) with MIDH. This study represents a new direction in the formation of defect‐free films of hybrid perovskites. 相似文献
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[C6H14N]PbBr3: An ABX3‐Type Semiconducting Perovskite Hybrid with Above‐Room‐Temperature Phase Transition 下载免费PDF全文
Jing Zhang Dr. Xitao Liu Xianfeng Li Shiguo Han Kewen Tao Yuyin Wang Chengmin Ji Prof. Zhihua Sun Prof. Junhua Luo 《化学:亚洲杂志》2018,13(8):982-988
Organic–inorganic hybrid perovskites, with the formula ABX3 (A=organic cation, B=metal cation, and X=halide; for example, CH3NH3PbI3), have diverse and intriguing physical properties, such as semiconduction, phase transitions, and optical properties. Herein, a new ABX3‐type semiconducting perovskite‐like hybrid, (hexamethyleneimine)PbBr3 ( 1 ), consisting of one‐dimensional inorganic frameworks and cyclic organic cations, is reported. Notably, the inorganic moiety of 1 adopts a perovskite‐like architecture and forms infinite columns composed of face‐sharing PbBr6 octahedra. Strikingly, the organic cation exhibits a highly flexible molecular configuration, which triggers an above‐room‐temperature phase transition, at Tc=338.8 K; this is confirmed by differential scanning calorimetry (DSC), specific heat capacity (Cp), and dielectric measurements. Further structural analysis reveals that the phase transition originates from the molecular configurational distortion of the organic cations coupled with small‐angle reorientation of the PbBr6 octahedra inside the inorganic components. Moreover, temperature‐dependent conductivity and UV/Vis absorption measurements reveal that 1 also displays semiconducting behavior below Tc. It is believed that this work will pave a potential way to design multifeatured perovskite hybrids by utilizing cyclic organic amines. 相似文献
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Fangjie Zhu Dr. Tatsuya Nishimura Dr. Takeshi Sakamoto Dr. Hidekazu Tomono Dr. Hiroki Nada Prof. Dr. Yasushi Okumura Prof. Dr. Hirotsugu Kikuchi Prof. Dr. Takashi Kato 《化学:亚洲杂志》2013,8(12):3002-3009
Thin‐film growth of aragonite CaCO3 on annealed poly(vinyl alcohol) (PVA) matrices is induced by adding Mg2+ into a supersaturated solution of CaCO3. Both the growth rate and surface morphology of the aragonite thin films depend upon the concentration of Mg2+ in the mineralization solution. In the absence of PVA matrices, no thin films are formed, despite the presence of Mg2+. Molecular dynamics simulation of the CaCO3 precursor suggests that the transition of amorphous calcium carbonate to crystals is suppressed in the presence of Mg2+. The role for ionic additives in the crystallization of CaCO3 on organic templates obtained in this study may provide useful information for the development of functional hybrid materials. 相似文献
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Miłosz Martynow Dr. Damian Głowienka Dr. Jędrzej Szmytkowski Dr. Yulia Galagan Dr. Julien Guthmuller 《Chemphyschem》2019,20(23):3228-3237
An experimental and theoretical investigation is reported to analyze the relation between the structural and absorption properties of CH3NH3PbI3 in the tetragonal phase. More than 3000 geometry optimizations were performed to reveal the structural disorder and identify structures with the lowest energies. The electronic structure calculations provide an averaged band gap of 1.674 eV, which is in excellent agreement with the experimental value of about 1.6 eV. The simulations of the absorption spectrum for three representative structures with lowest energy reproduced the absorption shoulders observed in the experimental spectra. These shoulders are assigned to excitations having similar orbital characters and involving transitions between hybridized 6s(Pb)/5p(I) orbitals and 6p(Pb) orbitals. The geometries of the three structures were analyzed and the effects of the inorganic frame and the CH3NH3+ cations on the absorption properties were estimated. It was found that both changes in the inorganic frame and the CH3NH3+ cations orientations impact the absorption spectra, by modifying the transitions energies and intensities. This highlights the role of CH3NH3+ cation in influencing the absorption properties of CH3NH3PbI3 and demonstrates that CH3NH3+ cation is one of the key elements explaining the broad and nearly constant absorption spectrum in the visible range. 相似文献
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Dr. Alessandra Alberti Dr. Ioannis Deretzis Dr. Giovanna Pellegrino Dr. Corrado Bongiorno Dr. Emanuele Smecca Dr. Giovanni Mannino Dr. Filippo Giannazzo Prof. Guglielmo Guido Condorelli Dr. Nobuya Sakai Prof. Tsutomu Miyasaka Dr. Corrado Spinella Dr. Antonino La Magna 《Chemphyschem》2015,16(14):3064-3071
We investigate the degradation path of MAPbI3 (MA=methylammonium) films over flat TiO2 substrates at room temperature by means of X‐ray diffraction, spectroscopic ellipsometry, X‐ray photoelectron spectroscopy, and high‐resolution transmission electron microscopy. The degradation dynamics is found to be similar in air and under vacuum conditions, which leads to the conclusion that the occurrence of intrinsic thermodynamic mechanisms is not necessarily linked to humidity. The process has an early stage, which drives the starting tetragonal lattice in the direction of a cubic atomic arrangement. This early stage is followed by a phase change towards PbI2. We describe how this degradation product is structurally coupled with the original MAPbI3 lattice through the orientation of its constituent PbI6 octahedra. Our results suggest a slight octahedral rearrangement after volatilization of HI+CH3NH2 or MAI, with a relatively low energy cost. Our experiments also clarify why reducing the interfaces and internal defects in the perovskite lattice enhances the stability of the material. 相似文献
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Rui Meng Guangbao Wu Jiyu Zhou Prof. Huiqiong Zhou Dr. Honghua Fang Prof. Maria A. Loi Prof. Yuan Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(21):5480-5488
A comprehensive study unveiling the impact of heterovalent doping with Bi3+ on the structural, semiconductive, and photoluminescent properties of a single crystal of lead halide perovskites (CH3NH3PbBr3) is presented. As indicated by single-crystal XRD, a perfect cubic structure in Bi3+-doped CH3NH3PbBr3 crystals is maintained in association with a slight lattice contraction. Time-resolved and power-dependent photoluminescence (PL) spectroscopy illustrates a progressively quenched PL of visible emission, alongside the appearance of a new PL signal in the near-infrared (NIR) regime, which is likely to be due to energy transfer to the Bi sites. These optical characteristics indicate the role of Bi3+ dopants as nonradiative recombination centers, which explains the observed transition from bimolecular recombination in pristine CH3NH3PbBr3 to a dominant trap-assisted monomolecular recombination with Bi3+ doping. Electrically, it is found that the mobility in pristine perovskite crystals can be boosted with a low Bi3+ concentration, which may be related to a trap-filling mechanism. Aided by temperature (T)-dependent measurements, two temperature regimes are observed in association with different activation energies (Ea) for electrical conductivity. The reduction of Ea at lower T may be ascribed to suppression of ionic conduction induced by doping. The modified electrical properties and NIR emission with the control of Bi3+ concentration shed light on the opportunity to apply heterovalent doping of perovskite single crystals for NIR optoelectronic applications. 相似文献
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Building Organic/Inorganic Hybrid Interphases for Fast Interfacial Transport in Rechargeable Metal Batteries 下载免费PDF全文
Qing Zhao Zhengyuan Tu Shuya Wei Kaihang Zhang Snehashis Choudhury Xiaotun Liu Prof. Lynden A. Archer 《Angewandte Chemie (International ed. in English)》2018,57(4):992-996
We report a facile in situ synthesis that utilizes readily accessible SiCl4 cross‐linking chemistry to create durable hybrid solid–electrolyte interphases (SEIs) on metal anodes. Such hybrid SEIs composed of Si‐interlinked OOCOR molecules that host LiCl salt exhibit fast charge‐transfer kinetics and as much as five‐times higher exchange current densities, in comparison to their spontaneously formed analogues. Electrochemical analysis and direct optical visualization of Li and Na deposition in symmetric Li/Li and Na/Na cells show that the hybrid SEI provides excellent morphological control at high current densities (3–5 mA cm?2) for Li and even for notoriously unstable Na metal anodes. The fast interfacial transport attributes of the SEI are also found to be beneficial for Li‐S cells and stable electrochemical cycling was achieved in galvanostatic studies at rates as high as 2 C. Our work therefore provides a promising approach towards rational design of multifunctional, elastic SEIs that overcome the most serious limitations of spontaneously formed interphases on high‐capacity metal anodes. 相似文献
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Allyloxyporphyrin‐Functionalized Multiwalled Carbon Nanotubes: Synthesis by Radical Polymerization and Enhanced Optical‐Limiting Properties 下载免费PDF全文
Dr. Aijian Wang Yu Fang Wang Yu Dr. Lingliang Long Prof. Dr. Yinglin Song Wei Zhao Dr. Marie P. Cifuentes Prof. Dr. Mark G. Humphrey Prof. Dr. Chi Zhang 《化学:亚洲杂志》2014,9(2):639-648
Allyloxyporphyrin‐functionalized multiwalled carbon nanotubes (MWCNT‐TPP) were synthesized by radical polymerization and characterized by FTIR, UV/Vis absorption, and X‐ray photoelectron spectroscopy; elemental analysis; TEM; and thermogravimetric analysis. Z‐scan studies revealed that this nanohybrid exhibits enhanced nonlinear optical (NLO) properties compared to a control sample consisting of a covalently unattached physical blend of MWCNTs and porphyrin, as well as to the separate MWCNTs and porphyrin. At the wavelengths used, the mechanism of enhanced optical limiting likely involves reverse saturable absorption, nonlinear scattering, and photoinduced electron/energy transfer between the MWCNTs and the porphyrin. The role of electron/energy transfer in the NLO performance of MWCNT‐TPP was investigated by Raman and fluorescence spectroscopy. 相似文献
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Efficient Hole Transporting Materials with Two or Four N,N‐Di(4‐methoxyphenyl)aminophenyl Arms on an Ethene Unit for Perovskite Solar Cells 下载免费PDF全文
Hyeju Choi Kwangseok Do Sojin Park Jong‐Sung Yu Prof. Jaejung Ko 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):15919-15923
Novel steric bulky hole transporting materials (HTMs) with two or four N,N‐di(4‐methoxyphenyl)aminophenyl units have been synthesized. When the EtheneTTPA was used as a hole transporting material in perovskite solar cell, the power conversion efficiency afforded 12.77 % under AM 1.5 G illumination, which is comparable to the widely used spiro‐OMeTAD based solar cell (13.28 %). 相似文献
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Enhancement of the Photovoltaic Performance of CH3NH3PbI3 Perovskite Solar Cells through a Dichlorobenzene‐Functionalized Hole‐Transporting Material 下载免费PDF全文
Jin‐Wook Lee Sungmin Park Dr. Min Jae Ko Dr. Hae Jung Son Prof. Nam‐Gyu Park 《Chemphyschem》2014,15(12):2595-2603
A dichlorobenzene‐functionalized hole‐transporting material (HTM) is developed for a CH3NH3PbI3‐based perovskite solar cell. Notwithstanding the similarity of the frontier molecular orbital energy levels, optical properties, and hole mobility between the functionalized HTM [a polymer composed of 2′‐butyloctyl‐4,6‐dibromo‐3‐fluorothieno[3,4‐b]thiophene‐2‐carboxylate (TT‐BO), 3′,4′‐dichlorobenzyl‐4,6‐dibromo‐3‐fluorothieno[3,4‐b]thiophene‐2‐carboxylate (TT‐DCB), and 2,6‐bis(trimethyltin)‐4,8‐bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′]dithiophene (BDT‐EH), denoted PTB‐DCB21] and the nonfunctionalized polymer [a polymer composed of thieno[3,4‐b]thiophene (TT) and benzo[1,2‐b:4,5‐b′]dithiophene (BDT), denoted PTB‐BO], a higher power conversion efficiency for PTB‐DCB21 (8.7 %) than that for PTB‐BO (7.4 %) is achieved because of a higher photocurrent and voltage. The high efficiency is even obtained without including additives, such as lithium bis(trifluoromethanesulfonyl)imide and/or 4‐tert‐butylpyridine, that are commonly used to improve the conductivity of the HTM. Transient photocurrent–voltage studies show that the PTB‐DCB21‐based device exhibits faster electron transport and slower charge recombination; this might be related to better interfacial contact through intermolecular chemical interactions between the perovskite and the 3,4‐dichlorobenzyl group in PTB‐DCB21. 相似文献
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Tris‐Functionalized Hybrid Anderson Polyoxometalates: Synthesis,Characterization, Hydrolytic Stability and Inversion of Protein Surface Charge 下载免费PDF全文
Amir Blazevic Emir Al‐Sayed Alexander Roller Prof. Dr. Gerald Giester Prof. Dr. Annette Rompel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(12):4762-4771
Single‐ and double‐sided functionalized hybrid organic–inorganic Anderson polyoxomolybdates with GaIII and FeIII positioned as central heteroatoms have been synthesized in a mild, two‐step synthesis in an aqueous medium. Compounds 1 – 4 were isolated as hydrated salts, [TBA]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×12 H2O ( 1 ) (TBA=tetrabutylammonium), Na3[FeMo6O18{(OCH2)3CCH2OH}2]×11 H2O ( 2 ), [TMA]2[GaMo6O18(OH)3{(OCH2)3CNH3}]×7 H2O ( 3 ) (TMA=tetramethylammonium), and Na[TMA]2[FeMo6O18(OH)3{(OCH2)3CNH3}](OH)×6 H2O ( 4 ). All the compounds were characterized based on single‐crystal X‐ray diffraction (SXRD), FTIR, UV/Vis, thermogravimetric, ESI‐MS, NMR, and elemental analyses. Compound 1 was also crystallized with two smaller organic cations, giving [TMA]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×n H2O ( 5 ) and [GDM]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×n H2O ( 6 ) (GDM=guanidinium) and were characterized based on UV/Vis, NMR, FTIR, and elemental analyses. The use of these compounds as additives in macromolecular crystallography was investigated by examining their hydrolytic stability by using ESI‐MS in a pH range of 4 to 9. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis showed that BSA remains intact in a solution containing up to 100 equivalents of 1 or 4 over more than four days at 20 °C. Zeta potential measurements demonstrate that 1 – 4 induce charge inversions on the positively charged surface of BSA (1 mg mL?1) with concentrations starting as low as 1.29 mM for compounds 1 and 2 , which have the highest negative surface charge. 相似文献
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Porous and Shape‐Anisotropic Single Crystals of the Semiconductor Perovskite CH3NH3PbI3 from a Single‐Source Precursor 下载免费PDF全文
Tom Kollek Dominik Gruber Julia Gehring Eugen Zimmermann Prof. Dr. Lukas Schmidt‐Mende Prof. Dr. Sebastian Polarz 《Angewandte Chemie (International ed. in English)》2015,54(4):1341-1346
Significant progress in solar‐cell research is currently made by the development of metal–organic perovskites (MOPs) owing to their superior properties, such as high absorption coefficients and effective transport of photogenerated charges. As for other semiconductors, it is expected that the properties of MOPs may be significantly improved by a defined nanostructure. However, their chemical sensitivity (e.g., towards hydrolysis) prohibits the application of methods already known for the synthesis of other nanomaterials. A new and general method for the synthesis of various (CH3NH3)PbI3 nanostructures from a novel single‐source precursor is presented. Nanoporous MOP single crystals are obtained by a crystal‐to‐crystal transformation that is accompanied by spinodal demixing of the triethylene glycol containing precursor structure. Selective binding of a capping agent can be used to tune the particle shape of the MOP nanocrystals. 相似文献
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Hao‐Hong Li Shu‐Wei Huang Zhao‐Xun Lian Ji‐Bo Liu Min Wang Prof. Dr. Zhi‐Rong Chen 《无机化学与普通化学杂志》2012,638(5):851-855
Two new polymeric iodoargentate hybrids induced by rare earth metal complexes and conjugated organic cations, {[Er(DMF)8][Ag6I9]}n ( 1 ) and [(MMP)(AgI2)]n ( 2 ) (MMP = 1‐methyl‐4‐methylpyridinium) were obtained by the routine synthetic reaction and structurally determined. In compound 1 , a (Ag6I9)n3n– chain is defined by edge‐sharing Ag6I12 units, and in 2 , the (Ag2I4)n2– chains are constructed by edge‐sharing AgI4 tetrahedra. C–H ··· I hydrogen bonds between cations and iodoargentate polyanions contribute to their structural extension from 1D to a 2D layer (for 1 ) and a 3D network (for 2 ). The UV/Vis spectra indicate that compared with 2 , compound 1 exhibits a narrower adsorption scope with an onset at about 360 nm, and it has a much wider bandgap of about 3.50 eV. 相似文献
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Dr. Suresh Babu Kalidindi Hyunchul Oh Dr. Michael Hirscher Dr. Daniel Esken Christian Wiktor Dr. Stuart Turner Prof. Dr. Gustaaf Van Tendeloo Prof. Dr. Roland A. Fischer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(35):10848-10856
Three‐dimensional covalent organic frameworks (COFs) have been demonstrated as a new class of templates for nanoparticles. Photodecomposition of the [Pd(η3‐C3H5)(η5‐C5H5)]@COF‐102 inclusion compound (synthesized by a gas‐phase infiltration method) led to the formation of the Pd@COF‐102 hybrid material. Advanced electron microscopy techniques (including high‐angle annular dark‐field scanning transmission electron microscopy and electron tomography) along with other conventional characterization techniques unambiguously showed that highly monodisperse Pd nanoparticles ((2.4±0.5) nm) were evenly distributed inside the COF‐102 framework. The Pd@COF‐102 hybrid material is a rare example of a metal‐nanoparticle‐loaded porous crystalline material with a very narrow size distribution without any larger agglomerates even at high loadings (30 wt %). Two samples with moderate Pd content (3.5 and 9.5 wt %) were used to study the hydrogen storage properties of the metal‐decorated COF surface. The uptakes at room temperature from these samples were higher than those of similar systems such as Pd@metal–organic frameworks (MOFs). The studies show that the H2 capacities were enhanced by a factor of 2–3 through Pd impregnation on COF‐102 at room temperature and 20 bar. This remarkable enhancement is not just due to Pd hydride formation and can be mainly ascribed to hydrogenation of residual organic compounds, such as bicyclopentadiene. The significantly higher reversible hydrogen storage capacity that comes from decomposed products of the employed organometallic Pd precursor suggests that this discovery may be relevant to the discussion of the spillover phenomenon in metal/MOFs and related systems. 相似文献