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Perovskite (structure)

About: Perovskite (structure) is a research topic. Over the lifetime, 51482 publications have been published within this topic receiving 1541750 citations.


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TL;DR: In this article, the authors investigated the charge transport properties of hybrid halide perovskites with a combination of density functional theory including van der Waals interaction and the Boltzmann theory for diffusive transport in the relaxation time approximation.
Abstract: The charge transport properties of hybrid halide perovskites are investigated with a combination of density functional theory including van der Waals interaction and the Boltzmann theory for diffusive transport in the relaxation time approximation. We find the mobility of electrons to be in the range 5–10 cm2V−1s−1 and that for holes within 1–5 cm2V−1s−1, where the variations depend on the crystal structure investigated and the level of doping. Such results, in good agreement with recent experiments, set the relaxation time to about 1 ps, which is the time-scale for the molecular rotation at room temperature. For the room temperature tetragonal phase we explore two possible orientations of the organic cations and find that the mobility has a significant asymmetry depending on the direction of the current with respect to the molecular axis. This is due mostly to the way the PbI3 octahedral symmetry is broken. Interestingly we find that substituting I with Cl has minor effects on the mobilities. Our analysis suggests that the carrier mobility is probably not a key factor in determining the high solar-harvesting efficiency of this class of materials.

285 citations

Journal ArticleDOI
TL;DR: In this paper, an interesting recycling-recyrstallization phenomenon of all-inorganic pervoskite, as well as its application on room temperature (RT) self-healing of compact and smooth carrier channels in ambient atmosphere for high-performance PDs with high stability is reported.
Abstract: The strong ionic character endows all-inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) with different chemical features from classical Cd-based NCs, especially when considering their interaction with polar solvents and surfactants. This has aroused intensive interest, but is still short of comprehensive understanding. More significantly, above characteristic may be used to improve the quality of perovskite thin films, which is crucial for the carrier transport inside optoelectronic devices. Here, an interesting recyclable dissolution–recyrstallization phenomenon of all-inorganic pervoskite, as well as its application on room temperature (RT) self-healing of compact and smooth carrier channels in ambient atmosphere for high-performance PDs with high stability is reported. First, according to solubility equilibrium principle, the size of CsPbBr3 crystals can be reversibly tuned in the range of 10 nm–1 μm through washing with polar solvent or stirring with assistance of surfactants at RT. Second, such phenomenon is applied for significant film quality improvement by forming a liquid circumstance within films, which can transport matter at surface and sharp parts into the gaps, healing themselves at RT. This strategy results in large-area, crack-free, low-roughness perovskite thin films. Obviously, such improvement facilitates transport and extraction of carriers in the channels of devices, which has been evidenced by the improvement of performances of the corresponding PDs at ambient condition.

285 citations

22 Apr 1993
TL;DR: In this article, the perovskite-type oxides SrCo0.8B'0.4CoO3?? and La0.6Sr 0.8Fe0.2O3?" were investigated and the occurrence of order-disorder transitions at elevated temperatures was confirmed by DSC measurements and, in some cases, by X-ray powder diffraction of samples either slowly cooled or quenched from high temperature after annealing in different atmospheres.
Abstract: New results on the oxygen permeability of perovskite-type oxides SrCo0.8B'0.2O3?? (with B'=Cr, Fe, Co and Cu) and La0.6Sr0.4CoO3?? are presented. The occurrence of order-disorder transitions at elevated temperatures (790?940°C) in these phases has been confirmed by DSC measurements and, in some cases, by X-ray powder diffraction of samples either slowly cooled or quenched from high temperature after annealing in different atmospheres. The oxygen permeability found upon exposing opposite sides of sealed disc specimens to a stream of air and of helium, respectively, increases sharply (between 5?6 orders of magnitude up to 0.3?3×10?7 mol cm?2s?1) at the onset of the transition from a low-temperature vacancy-ordered state to defec t perovskite, except for SrCo0.8Fe0.2O3??. In the latter case only a slight anomaly is found in the Arrhenius plot of th e oxygen permeability at 790°C. The comparatively high oxygen flux through SrCo0.8Fe0.2O3?? observed at intermediate tempe ratures is interpreted in terms of a two-phase mixture of a vacancy-ordered state and disordered perovskite, while above 790°C the sample is single-phase of defect perovskite structure.

285 citations

Journal ArticleDOI
TL;DR: A facile method is demonstrated to engineer the eg filling of perovskite cobaltite LaCoO3 for improving the oxygen evolution reaction activity, comparable to those of recently reported cobalt oxides with eg∼1.2 configurations.
Abstract: The activity of electrocatalysts exhibits a strongly dependence on their electronic structures. Specifically, for perovskite oxides, Shao-Horn and co-workers have reported a correlation between the oxygen evolution reaction activity and the eg orbital occupation of transition-metal ions, which provides guidelines for the design of highly active catalysts. Here we demonstrate a facile method to engineer the eg filling of perovskite cobaltite LaCoO3 for improving the oxygen evolution reaction activity. By reducing the particle size to ∼80 nm, the eg filling of cobalt ions is successfully increased from unity to near the optimal configuration of 1.2 expected by Shao-Horn’s principle. Consequently, the activity is significantly enhanced, comparable to those of recently reported cobalt oxides with eg∼1.2 configurations. This enhancement is ascribed to the emergence of spin-state transition from low-spin to high-spin states for cobalt ions at the surface of the nanoparticles, leading to more active sites with increased reactivity. The activity of electrocatalysts exhibits a strong dependence on their electronic structures. Here, the authors manipulate the eg filling of perovskite cobaltite LaCoO3nanoparticles by changing particle size and show improved oxygen evolution activity with increased numbers of surface high-spin cobalt ions.

285 citations

Journal ArticleDOI
TL;DR: In situ nanocrystallization strategy is developed to directly grow CsPbBr3 QDs among a specially designed TeO2-based glass matrix and QD-embedded glass shows typical bright green emission assigned to exciton recombination radiation and significant improvement of photon/thermal stability and water resistance due to the effective protecting role of dense structural glass.
Abstract: All-inorganic cesium lead bromide CsPbBr3 perovskite quantum dots (QDs) are emerging as potential candidates for their applications in optoelectronic devices but they suffer from poor long-term stability due to their high sensitivity to UV irradiation, heat, and especially to moisture. Although great advances in improving stability of perovskite QDs have been achieved by surface modification or encapsulation in polymer and silica, they are not sufficiently refrained from external environment due to nondense structures of these protective layers. In this work, in situ nanocrystallization strategy is developed to directly grow CsPbBr3 QDs among a specially designed TeO2-based glass matrix. As a result, QD-embedded glass shows typical bright green emission assigned to exciton recombination radiation and significant improvement of photon/thermal stability and water resistance due to the effective protecting role of dense structural glass. Particularly, ∼90% of emission intensity is even remained after immersi...

284 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20235,193
20229,857
20216,144
20205,859
20195,498
20184,741