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Showing 1 to 20 of 204 for “"perovskites"”.
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Topochemical Manipulation of Layered Perovskites
… those with divalent cations, within layered perovskites, opening the doors to compounds that can have interesting properties. <p>This reaction series was also applied to the tantalate layered oxides, leading to the formation of the new compound Ni</p> 0.5LaTa2O7 through ion exchange. The …
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Peculiar perovskites: Unraveling the unique optical response of hybrid organic-inorganic perovskites from first principles
Hybrid organic-inorganic perovskite (HOP) materials and their layered analogs (LHOP) have been extensively applied to optoelectronic applications including solar cells, light-emitting diodes, optical detectors, and spintronics due to their unique atomic, electronic, and optical properties. HOPs and …
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Microstructured Halide Perovskites for Energy Applications
Perovskites are cutting-edge materials that have demonstrated outstanding potential in the field of renewable energy. Their unique chemical-crystalline structure enables the easy substitution of atoms with various elements, allowing for a diverse range of optoelectronic properties that make them …
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Properties and Processing of Chalcogenide Perovskites
… optoelectronic materials, such as lead halides perovskites, have shown remarkable strides in optoelectronic performance, but they are plagued with issues of toxicity and stability. Chalcogenide perovskites have been proposed as potential replacements for these lead halide perovskites, but there …
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Synthesis and Characterization of Chalcogenide Perovskites
Chalcogenide perovskites are both an old and new group of materials. First synthesized in 1957, chalcogenide perovskites are generally sulfur and selenium compounds which contain a 3D network of corner-sharing octahedra. Not until 2015 was this material class recognized as being suitable for any …
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Theory of d₀ perovskites and their heterostructures
… between nonpolar SrTiO₃ (STO) with other polar perovskites has lead to an enormous amount of research. Among this 2DEGs most interesting properties are two-dimensional superconductivity and ferromagnetism, sometimes concurrent. This study provides a starting point in understanding the …
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Structure prediction, growth, and characterization of perovskites
… most of the elements of the periodic table. Perovskites have been the object of much study in the laboratory as well as being used extensively in industrial applications, with such properties as ferroelectricity, piezoelectricity, ferromagnetism, and superconductivity. First, I delineate the …
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Modelling of Structure-Property Relationships in Perovskites
… electronic properties of cubic metal-halide ABX3 perovskites (A=Cs,MA B=Pb,Sn X=Cl,Br,I) are modelled in order to elucidate phase-dependent electronic properties and systematic accuracy. These materials are of interest for solar cell applications, and are shown to be heavily dependent upon the …
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Local structure of hybrid metal-halide perovskites
… The local structure of the hybrid metal halide perovskites in the presence of static disorder was investigated using pair distribution function analysis of composition and temperature dependent X-ray and neutron total scattering of d6-MAPb(ClxBr1−x)3. It was found that both the local structure …
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Photophysics of Hybrid Perovskites with Electroactive Molecules
… organic cations into hybrid organic–inorganic perovskites offers a compelling strategy to unlock new optoelectronic functionalities by mediating the interaction between molecular orbitals and the inorganic lattice bands. Whereas conventional perovskites rely on electronically inert organic …
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Strain in Halide Perovskites: Characterisation, Crystallography, Consequences
… LEDs, and X-ray detectors making use of halide perovskites as the light absorbing or emitting material have experienced a dramatic increase in efficiency in recent years. As a result, halide perovskite-based solar cells are now starting to make their way out of laboratories and into the …
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Synthesis and sintering of nanostructured multicomponent perovskites
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1998.
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Microscale Energy Transport in Lead Halide Perovskites
… and design of semiconductor devices. Lead halide perovskites, an emerging semiconductor for optoelectronic applications, exhibits significant phenomena that can enhance or disrupt lateral energy transport, such as photon recycling and microscale heterogeneity. Understanding and quantifying these …
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Layered perovskites as cathode materials for IT-SOFC
… // = Ba or Sr and B = Transition Metals) layered perovskites improves the electrochemical performance due to the increase in electrical conductivity and smaller size difference between Ln+³ and Sr+². However these layered perovskites suffer from high thermal expansion coefficient (20-23 x 10-6 …
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Structural and electrical characterisation of some ABO₃ perovskites
… of the Raman profile and band position with perovskites with the same structure, namely, SmAlO₃ and LaGaO₃ and are as follows: 102 (B₁g ), ca.140 (B₂g), 150 (B₁g), 176 (Ag), 227 (B₃g), 261 (Ag), 289 (Ag), 413 (Ag), 429 (B₃g). LaFe₁₋ₓMgₓO₃ was prepared using a reverse-strike coprecipitation …
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Development of Metal Halide Perovskites for Memristor Applications
… as the insulator layer. Among them, halide perovskites have drawn extensive attention owing to their superb physical and electronic properties, including ambipolar carries transport, low defect density, tunable bandgap, long diffusion length, and so on. In this thesis, halide …
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New Ruddlesden-Popper Perovskites Obtained by Topochemical Methods
Topotactic routes have been used to produce new materials with tunable electronic and magnetic properties. The host materials were the single and triple layered Ruddlesden-Popper compounds, NaLnTiO4 (Ln = La and Gd) and A2La2Ti3O10 (A = Li and K). These compounds consist of [LnTiO4]- and …
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Synthetic exploration of halide perovskites and germanium semiconductors
<p>Halide perovskites and germanium semiconductors are promising materials for many optical applications such as solar cells and LEDs due to their unique photophysical properties. Compositional substitution and dimensional manipulation can enhance physical or chemical properties of perovskite and …
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Mixed Lead-Tin Halide Perovskites for Optoelectronic Applications
Mixed lead-tin (Pb-Sn) perovskites are unique materials in the family of halide perovskites. Unlike Pb perovskites, these mixed-metal systems can demonstrate bandgaps below 1.3 eV and are therefore essential constituents for low bandgap bottom subcell in all-perovskite tandem solar cells as well as …
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Tailoring Isothermal Redox Properties of Calcium-based Perovskites
… conditions such as high temperature, simple perovskites that can operate at comparatively lower temperatures and are carbon resistant are strongly desired. This challenge was undertaken in the present thesis, and for this purpose, CaMnO3 and its Fe substituted analogues were chosen. …
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