Synthesis, structure and optical properties of different dimensional organic-inorganic perovskites

By varying the substituent position of aminomethyl on pyridine ring in acid solution, different dimensional lead bromide frameworks ranging from zero-dimension and one-dimension to two-dimension were obtained. 2-(Aminomethyl)pyridine (2-AMP) or 3-(aminomethyl)pyridine (3-AMP) and PbBr2 construct hybrid perovskites, of which (H(2)2-AMP)PbBr4 (1) exhibits two-dimensional perovskite sheets with special hydrogen bonds and (H(2)3-AMP)PbBr6 (2) shows an uncommon zero-dimensional inorganic framework with isolated octahedra. The characteristic exciton peaks in absorption spectra are located at 431 nm for compound 1 and at 428 nm for compound 2. (H(2)4-AMP)PbBr4 (3) with one-dimensional zigzag edge-sharing octahedral PbBr(4)(2-)chains can be obtained using 4-(aminomethyl)pyridine (4-AMP) as organic component under the same experimental conditions as those for 2-AMP and 3-AMP.

New organic-inorganic perovskite materials with different optical properties modulated by different inorganic sheets

New organic-inorganic perovskites with different PbBr perovskite sheets stabilized by 3- or 4-an-tidinopyridine were synthesized and structurally characterized. 4-Amidinopyridine constructs < 001 >-oriented perovskite with inorganic sheets made up of typical corner-sharing octahedra of PbBr2. Analogous chemistry in the presence of 3-amidinopyridine under the same conditions results in an unusual hybrid perovskite with the inorganic sheets showing a novel framework including both corner-sharing and edge-sharing PbBr2, which is different from any previously reported ones.

Novel < 110 >-oriented organic-inorganic perovskite compound stabilized by N-(3-aminopropyl) imidazole with improved optical properties

In the organic-inorganic perovskites family, the < 100 >-oriented type has been extensively investigated as a result of its unique magnetic, optical, and electrical properties, and only one type of < 110 >-oriented hybrid perovskite stabilized by methylammonium and iodoformamidinium cations or the latter themselves has been known so far. In this paper, another novel < 110 >-oriented organic-inorganic perovskite (C6H13N3)-PbBr4 (compound 1) has been prepared by reacting N-(3-aminopropyl)imidazole (API) with PbBr2 in hydrobromic acid. The crystal structure is determined, which indicates that the perovskite is stabilized by API. The introduction of the optically active organic ligand API into the hybrid perovskite results in a red shift and a great enhancement of photoluminescence in the perovskite with respect to organic ligand API itself. These results have been explained according to calculation based on density-functional theory. Moreover, the excellent film processing ability for the perovskite (C6H13N3)PbBr4 together with the improved optical properties makes it have potential application in optoelectronic devices.

Fabrication of ZnO and its enhancement of charge injection and transport in hybrid organic/inorganic light emitting devices

ZnO nanocrystals were synthesized by hydrolysis in methanol. X-ray diffraction and photoluminescence spectra confirm that good crystallized ZnO nanoparticles were formed. Utilizing those ZnO nanoparticles and poly [2- methoxy-5 - (3',7'-dimethyloctyloxy)- 1,4-phenylenevinylene] (MDMO-PPV), light emitting devices with indium tin oxide (ITO)/poly(3,4-oxyethyleneoxy-thiophene):poly(styrene sulfonate) (PEDOT:PSS)/ ZnO:MDMO-PPV/Al and ITO/PEDOT:PSS/MDMO-PPV/Al structures were fabricated. Electrolummescence (EL) spectra reveal that EL yield of hybrid MDMO-PPV and ZnO nanocrystals devices increased greatly as compared with pristine MDMO-PPV devices. The current-voltage characteristics indicate that addition of ZnO nanocrystals can facilitate electrical injection and charge transport. The decreased energy barrier to electron injection is responsible for the increased efficiency of electron injection. (c) 2007 Elsevier B.V. All rights reserved.

Organic/inorganic hybrid solar cells based on SnS/SnO nanocrystals and MDMO-PPV

SnS/SnO heterojunction structured nanocrystals with zigzag rod-like connected morphology were prepared by using a simple two-step method. Bulk heterojunction solar cells were fabricated using the SnS/SnO nanocrystals blended with poly(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene) (MDMO-PPV) as the active layer. Compared with solar cells using SnS nanoparticles hybridized with MDMO-PPV as the active layer, the SnS/SnO devices showed better performance, with a power conversion efficiency higher by about one order in magnitude.

Synthesis and luminescence properties of hybrid organic-inorganic transparent titania thin film activated by in-situ formed lanthanide complexes

Stable transparent titania thin films were fabricated at room temperature by combining thenoyltrifluoroacetone (TTFA)-modified titanium precursors with amphiphilic triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, P123) copolymers. The obtained transparent titania thin films were systematically investigated by IR spectroscopy, PL emission and excitation spectroscopy and transmission electron microscopy. IR spectroscopy indicates that TTFA coordinates the titanium center during the process of hydrolysis and condensation. Luminescence spectroscopy confirms the in-situ formation of lanthanide complexes in the transparent titania thin film.

The research of rheology and thermodynamics of organic-inorganic hybrid membrane during the membrane formation

To clarify the mechanism of organic-inorganic hybrid membrane formation by phase-inversion method, the thermodynamical and theological properties of PSF/TiO2 casting solution were investigated by the viscosity measurement and the triangle phase diagram, respectively. TiO2 introduction decreased the non-solvent tolerance of casting solution with non-solvent 20% ethanol aqueous solution, which caused thermodynamic enhancement of phase separation, and also resulted in the change of theological properties from Newtonian fluid to non-Newtonian fluid and the viscosity increase of casting solution, which induced rheological hindrance in demixing process

Controlled synthesis of organic-inorganic hybrid nanofibers by a wet-chemical route

Organic-inorganic hybrid nanofibers are successfully synthesized by incorporating 3,3 ',5,5 '-tetramethylbenzidine (TMB) and H2PtCl6 at room temperature. The morphology and size can be simply controlled by tuning the molar ratio and initial concentration of reactants. A possible formation mechanism was suggested on the basis of the experimental results. The optical properties were investigated and the as-obtained product displays a strong fluorescence emission at room temperature that may be promising for applications in the fabrication of photoelectric materials. (C) 2008 Elsevier B.V. All rights reserved.

Organic-inorganic hybrid material for the cells immobilization: Long-term viability mechanism and application in BOD sensors

In this paper, organic-inorganic hybrid material, which is composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)), was employed to immobilize Trichosporon cutaneum strain 2.570 cells. Cells entrapped into the hybrid material were found to keep a long-term viability. The mechanism of such a long-term viability was investigated by using confocal laser scanning microscopy (CLSM). Our studies revealed that arthroconidia produced in the extracellular material might play an important role in keeping the long-term viability of the immobilized microorganism. After the arthroconidia were activated, an electrochemical biochemical oxygen demand (BOD) sensor based on cell/hybrid material-modified supporting membrane was constructed for verifying the proposed mechanism.

Synthesis, structure and optical properties of new organic-inorganic haloplumbates complexes (C5H10N3)PbX4 (X = Br, Cl), (C2H2N4)PbBr3

Layered organic-inorganic composite materials (C5H10N3)PbX4 (X = Br 1, Cl 2) containing histaminium dications were grown via a solution-cooling process, and their structure and optical properties were determined. The organic ligand-histaminium introduced into the corner-sharing octahedra of the 'PbX4- layer' contains both primary ammonium and imidazolium different from the traditionally primary amine found in this system. As comparison, another analogous amine of 3-amino-1,2,4-triazol was used as ligand to coordinate with PbBr2 in acid solution. A novel complex (C2H2N4)PbBr3 (3) was obtained with zigzag PbBr2 chains different from the PbX4 layer in compound as 1 and 2. The hybrid (C5H10N3)PbX4 show exciton absorption at 339 nm for X = Cl and 419 nm for X = Br with the corresponding emission at 360 and 436 nm, respectively. The different PbBr2 chain structure of compound 3 does not show photo luminescence.

Organic/inorganic nanocomposite polymer electrolyte

The organic/inorganic nanocomposites polymer electrolytes were designed and synthesized. The organic/inorganic nanocomposites membrane materials and their lithium salt complexes have been found thermally stable below 200 degrees C. The conductivity of the organic/inorganic nanocomposites polymer electrolytes prepared at room temperature was at magnitude range of 10(-6) S/cm. (c) 2007 Li Qi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Photoluminescent nanoparticles of organic-inorganic hybrids prepared by phase transfer complexation at the organic-aqueous solution interface

Monodispersed nanoparticles of Ag(I)-polymer hybrids have been prepared by using designed crown-ether-centred two-armed copolymers to chelate Ag+ ions at the interface of organic-aqueous solutions. The copolymer-Ag+ complex nanoparticles, as well as the reduced copolymer-Ag nanoparticles, have been characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). The particle size can be varied by simply changing the polymer concentration, the monomers, and/or the molecular weight. The copolymer-Ag(I) hybrids exhibit weak photoluminescence, which was substantially enhanced after the hybrids were reduced to copolymer-silver nanoparticles with UV irradiation.

Enhanced response induced by polyelectrolyte-functionalized ionic liquid in glucose biosensor based on sol-gel organic-inorganic hybrid material

In this work, a polyelectrolyte-functionalized ionic liquid (PFIL) was firstly incorporated into a sol-gel organic-inorganic hybrid material (PFIL/sol-gel). This new composite material was used to immobilize glucose oxidase on a glassy carbon electrode. An enhanced current response towards glucose was obtained, relative to a control case without PFIL. In addition, chronoamperometry showed that electroactive mediators diffused at a rate 10 times higher in the apparent diffusion coefficient in PFIL-containing matrices. These findings suggest a potential application in bioelectroanalytical chemistry.