Academic literature on the topic 'Perovskites form'

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Journal articles on the topic "Perovskites form"

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McDonald, Calum, Chengsheng Ni, Paul Maguire, Paul Connor, John Irvine, Davide Mariotti, and Vladimir Svrcek. "Nanostructured Perovskite Solar Cells." Nanomaterials 9, no. 10 (October 18, 2019): 1481. http://dx.doi.org/10.3390/nano9101481.

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Over the past decade, lead halide perovskites have emerged as one of the leading photovoltaic materials due to their long carrier lifetimes, high absorption coefficients, high tolerance to defects, and facile processing methods. With a bandgap of ~1.6 eV, lead halide perovskite solar cells have achieved power conversion efficiencies in excess of 25%. Despite this, poor material stability along with lead contamination remains a significant barrier to commercialization. Recently, low-dimensional perovskites, where at least one of the structural dimensions is measured on the nanoscale, have demonstrated significantly higher stabilities, and although their power conversion efficiencies are slightly lower, these materials also open up the possibility of quantum-confinement effects such as carrier multiplication. Furthermore, both bulk perovskites and low-dimensional perovskites have been demonstrated to form hybrids with silicon nanocrystals, where numerous device architectures can be exploited to improve efficiency. In this review, we provide an overview of perovskite solar cells, and report the current progress in nanoscale perovskites, such as low-dimensional perovskites, perovskite quantum dots, and perovskite-nanocrystal hybrid solar cells.
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Filip, Marina R., and Feliciano Giustino. "The geometric blueprint of perovskites." Proceedings of the National Academy of Sciences 115, no. 21 (May 7, 2018): 5397–402. http://dx.doi.org/10.1073/pnas.1719179115.

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Perovskite minerals form an essential component of the Earth’s mantle, and synthetic crystals are ubiquitous in electronics, photonics, and energy technology. The extraordinary chemical diversity of these crystals raises the question of how many and which perovskites are yet to be discovered. Here we show that the “no-rattling” principle postulated by Goldschmidt in 1926, describing the geometric conditions under which a perovskite can form, is much more effective than previously thought and allows us to predict perovskites with a fidelity of 80%. By supplementing this principle with inferential statistics and internet data mining we establish that currently known perovskites are only the tip of the iceberg, and we enumerate 90,000 hitherto-unknown compounds awaiting to be studied. Our results suggest that geometric blueprints may enable the systematic screening of millions of compounds and offer untapped opportunities in structure prediction and materials design.
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Wang, Fangfang, Qing Chang, Yikai Yun, Sizhou Liu, You Liu, Jungan Wang, Yinyu Fang, et al. "Hole-Transporting Low-Dimensional Perovskite for Enhancing Photovoltaic Performance." Research 2021 (May 28, 2021): 1–11. http://dx.doi.org/10.34133/2021/9797053.

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Halide perovskites with low-dimensionalities (2D or quasi-2D) have demonstrated outstanding stabilities compared to their 3D counterparts. Nevertheless, poor charge-transporting abilities of organic components in 2D perovskites lead to relatively low power conversion efficiency (PCE) and thus limit their applications in photovoltaics. Here, we report a novel hole-transporting low-dimensional (HT2D) perovskite, which can form a hole-transporting channel on the top surface of 3D perovskite due to self-assembly effects of metal halide frameworks. This HT2D perovskite can significantly reduce interface trap densities and enhance hole-extracting abilities of a heterojunction region between the 3D perovskite and hole-transporting layer. Furthermore, the posttreatment by HT2D can also reduce the crystal defects of perovskite and improve film morphology. As a result, perovskite solar cells (PSCs) can effectively suppress nonradiative recombination, leading to an increasement on photovoltage to >1.20 V and thus achieving >20% power conversion efficiency and >500 h continuous illumination stability. This work provides a pathway to overcome charge-transporting limitations in low-dimensional perovskites and delivers significant enhancements on performance of PSCs.
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Zhang, Taiyang, Yuetian Chen, Miao Kan, Shumao Xu, Yanfeng Miao, Xingtao Wang, Meng Ren, Haoran Chen, Xiaomin Liu, and Yixin Zhao. "MA Cation-Induced Diffusional Growth of Low-Bandgap FA-Cs Perovskites Driven by Natural Gradient Annealing." Research 2021 (August 18, 2021): 1–11. http://dx.doi.org/10.34133/2021/9765106.

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Low-bandgap formamidinium-cesium (FA-Cs) perovskites of FA1-xCsxPbI3 (x<0.1) are promising candidates for efficient and robust perovskite solar cells, but their black-phase crystallization is very sensitive to annealing temperature. Unfortunately, the low heat conductivity of the glass substrate builds up a temperature gradient within from bottom to top and makes the initial annealing temperature of the perovskite film lower than the black-phase crystallization point (~150°C). Herein, we take advantage of such temperature gradient for the diffusional growth of high-quality FA-Cs perovskites by introducing a thermally unstable MA+ cation, which would firstly form α-phase FA-MA-Cs mixed perovskites with low formation energy at the hot bottom of the perovskite films in the early annealing stage. The natural gradient annealing temperature and the thermally unstable MA+ cation then lead to the bottom-to-top diffusional growth of highly orientated α-phase FA-Cs perovskite, which exhibits 10-fold of enhanced crystallinity and reduced trap density (~3.85×1015 cm−3). Eventually, such FA-Cs perovskite films were fabricated into stable solar cell devices with champion efficiency up to 23.11%, among the highest efficiency of MA-free perovskite solar cells.
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Andrei, Florin, Rodica Zăvoianu, and Ioan-Cezar Marcu. "Complex Catalytic Materials Based on the Perovskite-Type Structure for Energy and Environmental Applications." Materials 13, no. 23 (December 5, 2020): 5555. http://dx.doi.org/10.3390/ma13235555.

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This review paper focuses on perovskite-type materials as (photo)catalysts for energy and environmental applications. After a short introduction and the description of the structure of inorganic and hybrid organic-inorganic perovskites, the methods of preparation of inorganic perovskites both as powders via chemical routes and as thin films via laser-based techniques are tackled with, for the first, an analysis of the influence of the preparation method on the specific surface area of the material obtained. Then, the (photo)catalytic applications of the perovskites in energy production either in the form of hydrogen via water photodecomposition or by methane combustion, and in the removal of organic pollutants from waste waters, are reviewed.
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Masharin, Mikhail, Oleksii Peltek, Pavel Talianov, Lev Zelenkov, Mikhail Zuyzin, and Sergey Makarov. "Upconversion photoluminescence of perovskite nanoparticles encapsulated in porous sub-micron spheres supporting Mie resonances." Journal of Physics: Conference Series 2015, no. 1 (November 1, 2021): 012089. http://dx.doi.org/10.1088/1742-6596/2015/1/012089.

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Abstract Currently, halide perovskites are very perspective materials not only for photovoltaics but also for nanophotonic and especially nonlinear optics. These materials have already demonstrated high two-, three- and many- photon absorption coefficients, strong Kerr-nonlinearity, and high-efficient second harmonic generation. Easy and cheap fabrication gives halide perovskites a wide area for scientific research and engineering applications. However, to achieve the stability of perovskites is still a challenging task, which scientific community is working on. In this work, we study a new form of encapsulation of perovskite nanoparticles in sub-micron porous dielectric nanospheres. Due to small pores in such spheres, perovskites are not only protected from external factors, but also are confined in size, which brings several features in the photoluminescence emission. We also show resonant properties of spherical sub-micron particles, which can be used for enhancing upconversion photoluminescence intensity.
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Hou, Yi, Erkan Aydin, Michele De Bastiani, Chuanxiao Xiao, Furkan H. Isikgor, Ding-Jiang Xue, Bin Chen, et al. "Efficient tandem solar cells with solution-processed perovskite on textured crystalline silicon." Science 367, no. 6482 (March 5, 2020): 1135–40. http://dx.doi.org/10.1126/science.aaz3691.

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Stacking solar cells with decreasing band gaps to form tandems presents the possibility of overcoming the single-junction Shockley-Queisser limit in photovoltaics. The rapid development of solution-processed perovskites has brought perovskite single-junction efficiencies >20%. However, this process has yet to enable monolithic integration with industry-relevant textured crystalline silicon solar cells. We report tandems that combine solution-processed micrometer-thick perovskite top cells with fully textured silicon heterojunction bottom cells. To overcome the charge-collection challenges in micrometer-thick perovskites, we enhanced threefold the depletion width at the bases of silicon pyramids. Moreover, by anchoring a self-limiting passivant (1-butanethiol) on the perovskite surfaces, we enhanced the diffusion length and further suppressed phase segregation. These combined enhancements enabled an independently certified power conversion efficiency of 25.7% for perovskite-silicon tandem solar cells. These devices exhibited negligible performance loss after a 400-hour thermal stability test at 85°C and also after 400 hours under maximum power point tracking at 40°C.
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Ben Haj Salah, Maroua, Justine Tessier, Nicolas Mercier, Magali Allain, Antonin Leblanc, Xiaoyang Che, Claudine Katan, and Mikael Kepenekian. "A 3D Lead Iodide Hybrid Based on a 2D Perovskite Subnetwork." Crystals 11, no. 12 (December 16, 2021): 1570. http://dx.doi.org/10.3390/cryst11121570.

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Lead halide perovskites have emerged as promising materials for various optoelectronic applications. For photovoltaics, the reference compound is the 3D perovskite (MA)PbI3 (MA+ = methylammonium). However, this material suffers from instabilities towards humidity or light. This makes the search of new stable 3D lead halide materials very relevant. A strategy is the use of intermediate size cations instead of MA, which are not suitable to form the 3D ABX3 perovskites or 2D perovskites. Here, we report on a novel 3D metal halide hybrid material based on the intermediate size cation hydroxypropylammonium (HPA+), (HPA)6(MA)Pb5I17. We will see that extending the carbon chain length from two CH2 units (in the hydroxylethylammonium cation, HEA+) to three (HPA+) precludes the formation of a perovskite network as found in the lead and iodide deficient perovskite (HEA,MA)1+xPbxI3−x. In (HPA)6(MA)Pb5I17 the 3D lead halide network results from a 2D perovskite subnetworks linked by a PbI6 octahedra sharing its faces. DFT calculations confirm the direct band gap and reveal the peculiar band structure of this 3D network. On one hand the valence band has a 1D nature involving the p orbitals of the halide. On the other, the conduction band possesses a clear 2D character involving hybridization between the p orbitals of the metal and the halide.
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Evans, Christopher D., Simon A. Kondrat, Paul J. Smith, Troy D. Manning, Peter J. Miedziak, Gemma L. Brett, Robert D. Armstrong, et al. "The preparation of large surface area lanthanum based perovskite supports for AuPt nanoparticles: tuning the glycerol oxidation reaction pathway by switching the perovskite B site." Faraday Discussions 188 (2016): 427–50. http://dx.doi.org/10.1039/c5fd00187k.

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Gold and gold alloys, in the form of supported nanoparticles, have been shown over the last three decades to be highly effective oxidation catalysts. Mixed metal oxide perovskites, with their high structural tolerance, are ideal for investigating how changes in the chemical composition of supports affect the catalysts' properties, while retaining similar surface areas, morphologies and metal co-ordinations. However, a significant disadvantage of using perovskites as supports is their high crystallinity and small surface area. We report the use of a supercritical carbon dioxide anti-solvent precipitation methodology to prepare large surface area lanthanum based perovskites, making the deposition of 1 wt% AuPt nanoparticles feasible. These catalysts were used for the selective oxidation of glycerol. By changing the elemental composition of the perovskite B site, we dramatically altered the reaction pathway between a sequential oxidation route to glyceric or tartronic acid and a dehydration reaction pathway to lactic acid. Selectivity profiles were correlated to reported oxygen adsorption capacities of the perovskite supports and also to changes in the AuPt nanoparticle morphologies. Extended time on line analysis using the best oxidation catalyst (AuPt/LaMnO3) produced an exceptionally high tartronic acid yield. LaMnO3 produced from alternative preparation methods was found to have lower activities, but gave comparable selectivity profiles to that produced using the supercritical carbon dioxide anti-solvent precipitation methodology.
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Long, Youwen. "High-pressure synthesis and physical properties of A-site ordered perovskites." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C755. http://dx.doi.org/10.1107/s2053273314092444.

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ABO3-type perovskite oxides exhibit a wide variety of interesting physical properties such as superconductivity, colossal magnetoresistance, multiferroic behavior etc. For a simple ABO3 perovskite, if three quarters of the A site is replaced by a transition metal A', then the so-called A-site ordered double perovskite with the chemical formula of AA'3B4O12 can form. Since both A' and B sites accommodate transition metal ions, in addition to conventional B-B interaction, the new A'-A' and/or A'-B interaction is possible to show up, giving rise to the presence of many novel physical properties. Here we will show our recent research work on the high-pressure synthesis of several A-site ordered perovskites as well as a series of interesting physical properties like temperature- and pressure-induced intermetallic charge transfer, negative thermal expansion, magnetoelectric coupling multiferroic and so on. [1-3]
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Dissertations / Theses on the topic "Perovskites form"

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Lee, Heejae. "Analysis of Current-Voltage Hysteresis and Ageing Characteristics for CH3NH3PbI3-xClxBased Perovskite Thin Film Solar Cells." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX009/document.

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Les perovskites organiques-inorganiques en halogénures de plomb sont des matériaux très prometteurs pour la prochaine génération de cellules solaires avec des avantages intrinsèques tels que leur faible coût de fabrication (grande disponibilité des matériaux de base et leur mise en œuvre à basse température) et leur bon rendement de conversion photovoltaïque. Cependant, les cellules solaires pérovskites sont encore instables et montrent des effets d'hystérésis courant-tension délétères. Dans cette thèse, des résultats de l’analyse physique de couches minces de pérovskite à base de CH3NH3PbI3-xClx et de cellules solaires ont été présentés. Les caractéristiques de transport électrique et les processus de vieillissement ont été étudiés avec différentes approches.Dans une première étape, la synthèse du matériau pérovskite a été optimisée en contrôlant les conditions de dépôt des films en une seule étape telles que la vitesse de rotation (6000 rpm) de la tournette et la température de recuit des films (80 °C). Dans un second temps, des cellules solaires perovskites à base de CH3NH3PbI3-xClx ont été fabriquées en utilisant la structure planaire inversée et caractérisées optiquement et électriquement.Grace à l’utilisation de la spectroscopie optique à décharge luminescente (GDOES), un déplacement des ions halogénures a été observé expérimentalement et de façon directe sous l’application d’une tension électrique. Une longueur de diffusion ionique de 140 nm et un rapport de 65% d'ions mobiles ont été déduits. Il est montré que l'hystérésis courant-tension dans l'obscurité est fortement affectée par la migration des ions halogénures provoquant un écrantage substantiel du champ électrique appliqué. Nous avons donc trouvé sous obscurité un décalage de la tension à courant nul jusque 0,25 V et un courant de fuite jusque 0,1 mA / cm2 en fonction des conditions de mesure. Grâce aux courbes courant-tension en fonction de la température, nous avons déterminé la température de transition de la conductivité ions/électrons à 260K et analysé les résultats expérimentaux en utilisant l'équation de Nernst- Einstein donnant une énergie d'activation de 0.253 eV pour les ions mobiles.Enfin, le processus de vieillissement de la cellule solaire a été étudié avec des mesures optiques et électriques. Nous avons déduit que le processus de vieillissement apparaît d'abord à la surface des cristaux de pérovskite ainsi qu’aux joints de grains. Les mesures GDOES nous indiquent que les caractéristiques électriques des cellules pérovskites sont perdues par une corrosion progressive de l'électrode supérieure en argent causée par la diffusion des ions iodures
Organic-inorganic lead halide perovskites are very promising materials for the next generation of solar cells with intrinsic advantages such as a low-cost material due to the availability of source materials and low-temperature solution processing as well as a high power conversion efficiency of the sunlight. However, perovskite solar cells are still unstable and show deleterious current-voltage hysteresis effects. Inthis thesis, analyses of CH3NH3PbI3-xClx based perovskite thin films and solar cells are presented. The electrical transport characteristics and the ageing processes are investigated using different approaches.The synthesis of the halide perovskite materials is optimized in a first step by controlling the deposition conditions such as annealing temperature (80°C) and spinning rate (6000 rpm) in the one step-spin-casted process. CH3NH3PbI3-xClx based perovskite solar cells are then fabricated in the inverted planar structure and characterized optically and electrically in a second step.Direct experimental evidence of the motion of the halide ions under an applied voltage has been observed using glow discharge optical emission spectroscopy (GDOES). Ionic diffusion length of 140 nm and ratio of mobile iodide ions of 65 % have been deduced. It is shown that the current-voltage hysteresis in the dark is strongly affected by the halide migration which causes a substantial screening of the applied electric field. Thus we have found a shift of voltage at zero current (< 0.25 V) and a leakage current (< 0.1 mA/cm2) in the dark versus measurement condition. Through the current-voltage curves as a function of temperature we have identified the freezing temperature of the mobile iodides at 260K. Using the Nernst-Einstein equation we have deduced a value of 0.253 eV for the activation energy of the mobile ions.Finally, the ageing process of the solar cell has been investigated with optical and electrical measurements. We deduced that the ageing process appear at first at the perovskite grain surface and boundaries. The electrical characteristics are degraded through a deterioration of the silver top-electrode due to the diffusion of iodides toward the silver as shown by GDOES analysis
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Bouich, Amal. "Study and Characterization of Hybrid Perovskites and Copper-Indium-Gallium Selenide thin films for Tandem Solar Cells." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/160621.

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[ES] El objetivo principal de esta tesis es contribuir al avance de nuevas técnicas de elaboración con bajo coste, utilizando materiales tipo de cobre, indio, galio y selenio CIGS y Perovskita para aplicaciones en energía solar fotovoltaica. CIGS parecen ser adecuadas ya que son de bajo costo de producción y se han reportado eficiencias de conversión del 23,35%. Por otro lado, las perovskitas híbridas de haluros de plomo orgánicos-inorgánicos han aparecido como nuevos materiales excepcionales para celdas solares, especialmente porque la eficiencia de las celdas solares basadas en perovskita ha aumentado del 3.8% al 22.7% en menos de un lustro. Este trabajo se ha dedicado a experimentar sobre la elaboración y caracterización de CIGS y los perovskitas de metilamonio de yoduro de plomo de (MAPbI3) y formamidinio de yoduro de plomo (FAPbI3), que se utilizo tanto en la aplicación a las células solares de perovskitas y en las células Tándem CIGS-perovskita. Las películas se caracterizaron por difracción de rayos X, espectroscopía Raman, microscopía electrónica de barrido, análisis de espectroscopía de energía dispersiva, microscopía de fuerza atómica, transmisión electrónica microscopía, fotoluminiscencia y espectroscopia UV-Vis. En las capas de CIGS depositadas por electrodeposición se investigó el efecto de diferentes parámetros, También investigamos en detalle el efecto del contacto posterior en las propiedades estructurales y ópticas de CIGS. Constatamos que el tipo de contacto posterior tiene un efecto significativo en el rendimiento posterior de las películas delgadas CIGS. Además, estudiamos la técnica de espray pirólisis para producir películas CIGS. Se estudió el proceso de recocido, que es el factor clave para mejorar el rendimiento de las células solares. Se elaboraron diferentes películas delgadas constituidas de nuestro dispositivo CdZnS/CdS/CIGS/Mo eso utilizó una capa conductora transparente de CdZnS para minimizar la alineación de la interfaz. Por otro lado, se analizó el proceso de cristalización y la estabilidad de las capas MAPbI3. Las capas de MAPbI3 se trataron añadiendo antisolvente a diferentes velocidades. Durante el tratamiento se producen intercambios complejos que influencian muchas propiedades fisicoquímicas. Se investigaron las propiedades ópticas y eléctricas de las películas de MAPbI3. Para mejorar la estabilidad de MAPbI3, se incorporó tetrabutilamonio (TBA), observando una mejora en la formación de la estructura perovskita que crece en la dirección preferente (110). La fase cristalina de MAPbI3 dopada con TBA presenta mejor cristalinidad, gran tamaño de grano, morfología superficial sin poros lo que es adecuado para la fabricación de dispositivos optoelectrónicas con mayor rendimiento. Además, hemos identificado el impacto de TBA en las propiedades foto físicas de MAPbI3. En las muestras de TBA:MAPbI3 aumenta la intensidad de la fotoluminiscencia al reducir la densidad de los estados de trampa y la absorción óptica muestra un cambio significativo hacia longitudes de onda más largas y la banda prohibida óptica varió de 1.8 a 1.52 eV. Finalmente, las muestras dopadas con 5% TBA mejoraron su estabilidad y se encontró que después de 15 días la estabilidad permanecía excelente en una humedad de ~ 60%. Por otra parte, investigamos el efecto de guanidinio (GA) sobre las propiedades estructurales y ópticas de FAPbI3. La relación entre la fase a de perovskita deseable y la fase indeseable y se ha estudiado en función del contenido de GA. Se comprobó que el dopaje con GA es eficaz en el control de la relación de fases a/y y luego en la estabilización de la fase a. Los resultados muestran que añadiendo una cantidad adecuada del 10% GA conduce a una mejora de película de perovskita que se evidencia en la homogeneidad de la fase a estable, granos de mayor tamaño y capas libres de poros. Además, 10% GA:FaPbI3 demostraron una excelente estabilidad después de ser envejecidas durante 15 días en un ambiente con humedad relativa del 60%.
[EN] The thesis work presented is part of the work in the Laboratory of New Materials for Photovoltaic Energy in the main target to use low cost techniques for elaboration of Perovskite and Copper, indium, gallium, and selenium CIGS materials for photovoltaic application. Organic-inorganic lead halides perovskites have currently and exceptionally appeared as new materials for low cost thin film solar cells specially that the efficiency of perovskite based solar cell have jumped from 3.8% to 22.7% in short time.in other hand, CIGS solar cells record 23.35% efficiency and still can be boosted. Here, we report the elaboration and characterization of CIGS as well as methylammonium lead iodide perovskites MAPbI3 and formamidinuim iodide lead iodide perovskites FAPbI3 absorbers for perovskite-based solar cells and Tandem Perovskites/ CIGS. The thin films prepared were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis, atomic force microscopy (AFM), transmission electron microscopy (TEM), Photoluminescence analysis (PL) and UV-Vis spectroscopy. The first stage was devoted for the effect of different parameters on the growth of CIGS by electrodeposition and we investigate the impact of different back contact in structural and optical proprieties. In a second stage, we report the growth of CIGS films by spray pyrolysis, we studied the effect of experimental parameter also the annealing process which is the key factor for improving the performance of solar cells,subsequently we elaborated different films constituted CdZnS/CdS/CIGS/Mo solar cells, the approach is to change the toxic ZnO by using a transparent, conductive CdZnS layer. In other hand, MAPbI3 film was investigated in order to optimize the chemical composition and to study the crystallization process also to get sight about the stability of perovskite materials to meet the requirement of their application as an active layer in perovskite solar cell. For this purpose. the MAPbI3 film surface was treated by adding diethyl ether antisolvent with different rates. during the treatment complex exchanges are appearing at the same time under the influence of quite a lot of physicochemical properties. A whole understanding of this topic is critically important for improving solar cell performance. MAPbI3 doped by the tetrabutylammonium TBA is boosting the formation of perovskite structure, leading to a higher orientation along the (110) and shows better crystallinity, large grain size, pinhole-free, which is suitable for the manufacturing of the optoelectronic devices with higher performance. Also, we have identified the impact of TBA in the photo-physical properties, we have noticed that the TBA improve the photoluminescence emission by reducing the density of trap states and the optical absorption indicates a significant shift to the lower wavelength and optical bandgap varied from 1.8 to 1.52 eV. Finally, the stability was explored for 5% TBA, it found that after 15 days the stability remained excellent in relative humidity of ~60%. These results would be helpful for realizing stable and high performance MAPbI3-based devices. Furthermore, we inspect the effect of monovalent cation substitution of Guanidinium (GA) on the structural and optical properties of FAPbI3 thin films perovskites. The ratio between the desirable a-phase and the undesirable y yellow phase is studied as a function of GA content. GA doping is shown to be efficient in the control of a/y phases ratio and then in the stabilization of the a-FaPbI3 phase. We qualitatively evaluate the impact of 10% of guanidinium on the phase composition and microstructure of films. The results show that an adequate amount of 10% GA:FaPbI3 leads to a homogeneous perovskite film with stable a phase, large grains, and free pinholes. 10% GA: FaPbI3 films demonstrate excellent stability after aging for 15 days in relative humidity of~60%.
[CA] L'objectiu principal d'aquesta tesi és contribuir a l'avanç de noves tècniques d'elaboració de baix cost, fent servir materials d'aliatges del tipus de coure, indi, gal·li i seleni (CIGS) i perovskites, per a aplicacions en energia solar fotovoltaica. El CIGS sembla ser adequat ja que són de baix cost de producció i s'han reportat eficiències de conversió del 23,35%. D'altra banda, les perovskites híbrides d'halurs de plom orgànics-inorgànics han aparegut com a nous materials excepcionals per cel·les solars, especialment perquè l'eficiència de les cel·les solars basades en perovskites ha augmentat del 3.8% al 22.7% en menys d'un lustre. En el present treball, reportem l'elaboració i caracterització de CIGS y de perovskitas de iodur de plom de metilamoni (MAPbI3) i de iodur de plom de formamidini (FaPbI3) per a les cèl·lules solars de CIGS i tàndem Perovskites/CIGS. En les capes de CIGS dipositades per electrodeposició es va investigar l'efecte dels diferents paràmetres sobre el procés d'electrodeposició, així com l'efecte del contacte posterior sobre les propietats estructurals i òptiques del CIGS. Ens trobem que el tipus de contacte posterior té un efecte significatiu en la posterior interpretació de pel·lícules primes CIGS. A més, vam estudiar la tècnica de polvorització de la piròlisi per produir pel·lícules de CIGS. Es va estudiar el procés de recuit, que és el factor clau per millorar el rendiment de les cèl·lules solars. Es van produir diferents pel·lícules fines formades pel nostre dispositiu CdZnS/CdS/CIGS/Mo que utilitzaven una capa conductiva CdZnS transparent per minimitzar l'alineació de la interfície. D'altra banda, es van investigar perovskites MAPbI3, amb la finalitat d'optimitzar la composició química i estudiar el procés de cristal·lització també per a conèixer l'estabilitat dels materials de perovskita. la cristal·lització s'aconsegueix alentint la solubilitat en una solució saturada mitjançant l'addició d'una quantitat diferent de l'antisolvent d'èter dietílic. Durant el tractament apareixen al mateix temps intercanvis complexos sota la influència de moltes propietats fisicoquímiques. Una comprensió completa d'aquest tema és de vital importància per a millorar el rendiment. Amb l'objectiu principal d'augmentar l'estabilitat de MAPbI3, el tetrabutilamoni (TBA) es pot incorporar a MAPbI3, impulsant la formació de l'estructura de perovskita, la qual cosa porta a una major orientació al llarg de (110). MAPbI3 dopades amb TBA presenten una millora de la cristalinitat, major grandària, la qual cosa és adequada per a la fabricació de dispositius optoelectròniques de major rendiment. A més, hem identificat l'impacte de TBA en les propietats foto físiques de MAPbI3. Hem notat que el dopatge amb TBA millora tant l'emissió de la fotoluminiscència en reduir la densitat dels estats de trampes com l'absorció òptica on apareix un canvi significatiu de la banda òptica prohibida cap a longituds d'ona més llargues que significa disminuir l'energia del gap, que va variar de 1.8 a 1.52 eV. Finalment, es va explorar l'estabilitat per les perovsquites dopades amb 5%TBA. Es va trobar que després de 15 dies l'estabilitat romania excel·lent en un humitat de 60%. A més, hem estudiat FAPbI3 com un dels materials de perovskita més atractius. Hem investigat l'efecte de la substitució de guanidini (GA) sobre les propietats estructurals i òptiques de FAPbI3. La relació entre la fase a de perovskita desitjable i la fase indesitjable y es va estudiar en funció del contingut de GA. Es mostra que el dopatge amb GA és eficaç en el control de la relació de fases a /y i després en l'estabilització de la fase a-FaPbI3. Els resultats mostren que una quantitat adequada de 10% GA condueix a una pel·lícula homogènia amb fase a estable, grans grans lliures de porus i forats. Les pel·lícules de 10% GA:FaPbI3 demostraren una excel·lent estabilitat després de l'envelliment durant 15 dies en un ambient humit (humitat relativa de 60%).
Bouich, A. (2020). Study and Characterization of Hybrid Perovskites and Copper-Indium-Gallium Selenide thin films for Tandem Solar Cells [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160621
TESIS
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Ljungström, Elin, Ellen Hådén, Lukas Lekberg, and Nima Taherpour. "Design, synthesis and characterization of Dimethylammonium / Ethylammonium / Cesium Lead Halide Perovskites for optoelectronic applications." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277109.

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The world is facing a climate crisis and to be able to solve it society needs to decrease the use of fossil fuels and find renewable alternatives. Solar energy is a great contender for a renewable energy source since it can be harvested for eternal time. One of the problems with the solar cells available today is that they are more expensive than fossil alternatives, and the process of making them still uses a lot of resources and energy. However, in the last decade an alternative has arisen; perovskite solar cells. Due to the fact that perovskite solar cell production uses less energy and resources than the current silicon solar cell, perovskite solar cells are more cost effective. The main problem with perovskite solar cells is that they are too unstable and do not last very long. One way to stabilize them is to introduce one more cation and make hybrid perovskites. The purpose of this project was to synthesize a perovskite material with the chemical formula AA’PbI3 (A = Cs, A’ = dimethylammonium or ethylammonium) to see if any of the compositions would generate a stable black cubic phase, which is the optimal phase of the perovskite. Mesoporous N-I-P solar cells were created by a layer by layer deposition method. The perovskite layer was added using a spin-coater to deposit the perovskite solution. The films were then characterized using XRD and UV/Vis absorption spectroscopy. Due to the coronavirus pandemic of 2020, the hole transport material and gold electrode were not added to the solar cell. As a consequence of this, not all of the compositions were synthesised which also means that the results are not conclusive. It was observed that all of the films were yellow, which indicates that none of the perovskites achieved a cubic structure. An explanation could be that some parts of the synthesis needs to be done inside a glove box where the environmental variables like humidity could be controlled. The XRDs show that some films had the expected perovskite composition, while some perovskites had decomposed into its starting materials. For hybrid components and pure ethylammonium perovskite film it was harder to confirm our conclusion since no characterization of single crystals was available for these components. However, it was determined that the addition of cesium did make the perovskites more stable.
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McDonald, Calum James. "Alternative perovskites for photovoltaics." Thesis, Ulster University, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.722581.

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This thesis explores new types of perovskite and perovskite-like materials for photovoltaics, with a view towards demonstrating novel and low-cost materials such as metal oxide perovskites for photovoltaics. The first part explores the prototypical organometal halide perovskite CH3NH3Pbl3, where CH3NH3 = methylammonium (MA). MAPbl3 has been studied by the partial replacement of its organic component, MA, with the larger molecule ethylenediammonium (EDA), with the chemical formula NH3(CH2)2NH3. This in turn introduces vacancies into EDA-containing MAPbl3, which has allowed the study of a non-stoichiometric organometal halide perovskite. This work observed that the partial replacement of the MA molecule with a larger molecule reduced the hysteresis. Following this, the low-cost perovskite-like material methylammonium iodo bismuthate has been studied. Methylammonium iodo bismuthate has the chemical formula MA3Bi2lg (MABI), and forms a zero­dimensional network of Bi2lg bioctahedra with quantum confinement. MABI has been characterised and used to fabricate solar cells. This bulk material with an ordered zero-dimensional internal structure exhibits carrier multiplication, and this thesis has demonstrated the fabrication of MABI solar cells. The structure has also been shown to favourably accommodate a small quantity of quantum confined silicon nanocrystals, opening up an avenue of possible hybrid devices which can be explored. Building on this knowledge, this thesis then explores two perovskite oxide materials which have not previously been demonstrated in photovoltaics. Both perovskite oxides exhibit strong and broad visible light absorption which extends into the near-infrared spectrum. One of which, Sr-deficient strontium niobate (Sro.gNb03), exhibits metallic conduction, and has been demonstrated in a photovoltaic cell for the first time. This work demonstrates the possibility of extracting excited carriers in a metal oxide with metallic conduction. The metal oxide perovskite calcium manganite, Ca2Mn2O5, has also been explored for photovoltaics. Ca2Mn2O5 is a plasmonic metal oxide and is therefore highly attractive material for photovoltaics. Solar cells were successfully fabricated using Ca2Mn2O5, and these results demonstrate the possibility of carrier extraction and highlight great opportunities for solar energy harvesting.
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Yao, Disheng. "Interfacial and compositional engineering of perovskite solar cells for enhanced device performance and stability." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/202693/1/Disheng_Yao_Thesis.pdf.

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This project was a comprehensive study of interfacial and compositional engineering on perovskite solar cells (PSCs). Significantly enhanced power conversion efficiency and device lifetime of PSC photovoltaic technology were achieved by ion doping based on solution-processed and vapour-assisted treatments. The effects of various amine-contained ligands on enhancing performance of PSC were systematically investigated to reveal controlling defects and interfacial properties in the materials. This work provides several new insights into perovskite solar cells. The research outcomes benefit the development of PSCs based photovoltaic technology.
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Ovalle, Alejandro. "Manganese titanium perovskites as anodes for solid oxide fuel cells." Thesis, St Andrews, 2008. http://hdl.handle.net/10023/567.

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Papargyriou, Despoina. "Materials and catalysts incorporation for the fuel oxidation layer of oxygen transport membranes." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/12113.

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Oxygen Transport Membranes (OTMs) can drastically reduce the energy and cost demands of processes that require pure oxygen, as they offer the possibility to combine a separation unit with a chemical reactor. One of the most commercially viable applications of OTMs is the partial oxidation of hydrocarbons for syngas production. A typical OTM configuration is a sequential arrangement of layers, i.e. an inactive support, a fuel oxidation layer, a dense layer and an oxygen reduction layer. However, one of the limitations of the OTM system is the low catalytic activity and stability of the materials currently used for the fuel oxidation layer. Moreover, the traditional deposition techniques that are used for the catalysts preparation are difficult to perform, as the fuel oxidation layer is buried deeply in the structure of the OTM. To simplify the OTM fabrication and improve the catalysts activity and stability, this thesis explores the exsolution of Ni nanoparticles from two different host lattice compositions, as potential materials for the fuel oxidation layer of OTMs. The (La₀.₇₅Sr₀.₂₅)(Cr₀.₅Mn₀.₄₅Ni₀.₅)O₃ (LSCMNi5) perovskite was selected, as the first candidate material for the OTMs. During reduction, the exsolution of Ni nanoparticles from the perovskite lattice took place and enhanced significantly the catalytic activity of the material regarding methane conversion. However, these nanoparticles were oxidised during the first hours of the testing and slowly reincorporated into the perovskite structure, leading to drop in the performance. Thereafter, the (La₀.₇₅Sr₀.₂₅)(Cr₀.₅Mn₀.₄₅Ni₀.₅)O₃ (LSCMNi5) perovskite was selected as an alternative composition. When the oxide lattice was sufficiently reduced, the exsolution of Fe-Ni alloy nanoparticles occurred. The catalytic testing suggested that the Fe-Ni alloy nanoparticles on LSCFNi5 presented lower activity for methane conversion comparing to the Ni nanoparticles on LSCMNi5, but higher stability in oxidising conditions. By increasing the Ni doping on the B-site of LSCF to 15 mol%, the catalytic activity of the material regarding methane conversion was increased and exceeded that of LSCMNi5. A CH₄ conversion of 70% was achieved, which was 20 times higher than that of the initial LSCF perovskite. Therefore, by tailoring the perovskite composition and the exsolution of the Fe-Ni alloy nanoparticles, it was possible to synthesize a material for the fuel oxidation layer of OTMs, which combined the high catalytic activity of Ni and the good redox stability of Fe.
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Kang, Sung Gu. "Dense metal and perovskite membranes for hydrogen and proton conduction." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/48944.

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First- principles modeling is used to predict hydrogen permeability through Palladium (Pd)-rich binary alloy membranes as a function of temperature and H2 pressure. We introduce a simplified model that incorporates only a few factors and yields quantitative prediction. This model is used to predict hydrogen permeability in a wide range of binary alloy membranes and to find promising alloys that have high hydrogen permeability. We show how our efficient Density Functional Theory (DFT)-based model predicts the chemical stability and proton conductivity of doped barium zirconate (BaZrO3), barium stannate (BaSnO3), and barium hafnate (BaHfO3). Our data is also used to explore the physical origins of the trends in chemical stability and proton conductivity among different dopants. We also study potassium tantalate (KTaO3), which is a prototype perovskite, to examine the characteristics of undoped perovskites. Specifically, we study the impacts of isotope effects, tunneling effects, and native point defects on proton mobility in KTaO3. It is important to find and develop solid-state Li-ion electrolyte materials that are chemically stable and have high ionic conductivities for high performance Li-ion batteries. We show how we predict the chemical stability of Li7La3Zr2O12, Li7La3Sn2O12, and Li7La3Hf2O12 with respect to carbonate and hydroxide formation reactions.
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Roknuzzaman, Md. "Ab initio atomistic insights into lead-free perovskites for photovoltaics and optoelectronics." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/198196/1/Md_Roknuzzaman_Thesis.pdf.

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This project focuses on the development of advanced non-toxic materials for the applications in energy generation and consumption devices like solar cells, light-emitting diodes, lasers and photodetectors. A first-principles density functional theory calculations are conducted to investigate the properties of a number of inorganic, hybrid and double perovskites compounds to predict their potential for applications in photovoltaics and optoelectronics. The achieved outcomes provide a better understanding of the structural, electronic, optical and mechanical properties of a group of potential compounds and provide new scientific knowledge to develop non-toxic high-quality organic-inorganic materials for photovoltaic and optoelectronic applications.
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Peng, Yong. "Hybrid Lead Perovskites as Photocatalysts and Materials for Photo- and Electrocatalytic N2 Reduction." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/171731.

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Tesis por compendio
[ES] La conversión de energía solar a productos químicos se considera una de las estrategias más viables para abordar los problemas derivados del uso masivo de combustibles fósiles y la excesiva emisión antropogénica de CO2. En catálisis asistida con luz, incluida la fotocatálisis y la catálisis fototérmica, el punto clave es el desarrollo de fotocatalizadores eficientes y robustos que puedan utilizar al máximo la energía solar y que sean lo suficientemente estables como para su comercialización. Los materiales basados en perovskitas híbridas orgánicas-inorgánicas han revolucionado el campo de la fotovoltaica en la última década, alcanzando una eficiencia de conversión de luz solar del 23%. Dado que los campos de la fotocatálisis y la fotovoltaica comparten procesos comunes, se abre la posibilidad de aplicación de estos materiales en fotocatálisis. Con el objetivo de confirmar esta posible aplicación de las perovskitas híbridas en fotocatálisis, en esta Tesis Doctoral, se han sintetizado nuevos materiales híbridos de perovskita con el objetivo de mejorar su estabilidad frente a la humedad aprovechando la gran variedad de ligandos orgánicos disponibles, que además pueden ser usados para promover modificaciones superficiales capaces de ajustar las propiedades hidrofílicas / hidrofóbicas. La actividad fotocatalítica de estos nuevos materiales de perovskita se ha estudiado en reacciones modelo para confirmar su estabilidad en las condiciones de reacción. Por otro lado, la reacción de fijación de nitrógeno fotoasistida también ha sido estudiada en detalle en esta Tesis Doctoral. Por un lado, se han sintetizado, caracterizado y testado nuevos complejos organometálicos como foto- y electrocatalizadores homogéneos para esta reacción. Estos han demostrado ser capaces de activar la molécula de dinitrógeno bajo un potencial electroquímico de reducción para formar amoníaco. Por otro lado, se han preparado nanopartículas de rutenio depositadas sobre un material de perovskita a base de titanato como fotocatalizador heterogéneo para la producción de amoniaco en flujo continuo. Además, se ha demostrado que la incorporación de metales alcalinos a este fotocatalizador puede potenciar su actividad fotocatalítica en esta reacción. Así, este material compuesto ha demostrado estar entre los fotocatalizadores más eficientes del estado del arte en la actualidad para esta reacción demostrando además una su elevada estabilidad en las condiciones de reacción.
[CA] La conversió d'energia solar en productes químics es considera una de les estratègies més viables per abordar els problemes derivats de l'ús massiu de combustibles fòssils i l'excessiva emissió antropogènica de CO2. En catàlisi assistida amb llum, inclosa la fotocatàlisi i la catàlisi fototèrmica, el punt clau és el desenvolupament de fotocatalitzadors eficients i robustos que puguen utilitzar al màxim l'energia solar i que siguen prou estables com per a la seva comercialització. Els materials basats en perovskites híbrides orgàniques-inorgàniques han revolucionat el camp de la fotovoltaica en l'última dècada, aconseguint una eficiència de conversió de llum solar del 23%. Atès que els camps de la fotocatàlisi i la fotovoltaica comparteixen processos comuns, s'obre la possibilitat d'aplicació d'aquests materials en fotocatàlisi. Amb l'objectiu de confirmar aquesta possible aplicació de les perovskites híbrides en fotocatàlisi, en aquesta tesi doctoral, s'han sintetitzat nous materials híbrids de perovskita amb l'objectiu de millorar la seva estabilitat enfront de la humitat aprofitant la gran varietat de lligands orgànics disponibles, que amés poden ser usats per a promoure modificacions superficials capaços d'ajustar les propietats hidrofíliques / hidrofòbiques. L'activitat fotocatalítica d'aquests nous materials de perovskita s'ha estudiat en reaccions model per confirmar la seva estabilitat en les condicions de reacció. D'altra banda, la reacció de fixació de nitrogen fotoassistida també ha sigut estudiada en detall en aquesta tesi doctoral. D'una banda, s'han sintetitzat, caracteritzat i testat nous complexos organometàl·lics com foto- i electrocatalitzadors homogenis per a aquesta reacció. Aquests han demostrat ser capaços d'activar la molècula de dinitrogen sota un potencial electroquímic de reducció per formar amoníac. D'altra banda, s'han preparat nanopartícules de ruteni depositades sobre un material de perovskita a força de titanat com fotocatalitzador heterogeni per a la producció d'amoníac en flux continu. A més, s'ha demostrat que la incorporació de metalls alcalins a aquest fotocatalitzador pot potenciar la seva activitat fotocatalítica en aquesta reacció. Així, aquest material compost ha demostrat estar entre els fotocatalitzadors més eficients de l'estat de l'art actualment per a aquesta reacció seva demostrant amés una elevada estabilitat en les condicions de reacció.
[EN] Solar energy to chemicals conversion is regarded to be one of the most plausible strategies addressing the issues of fossil fuel crisis and excessive anthropogenic CO2 emission. For photo-assisted catalysis, including photocatalysis and photothermal catalysis, the key point is the development of efficient and robust photocatalysts that can efficiently utilize the solar energy as well as they are stable enough that meets the requirements for commercialization. Hybrid organic-inorganic perovskites have revolutionized the photovoltaic field in the last decade, reaching a certified sunlight conversion efficiency of 20 %. Since photocatalysis and photovoltaics share common processes, the application of these materials in photocatalysis would be possible. In this Doctoral Thesis, novel hybrid perovskite materials have been synthesized with the aim to improve their stability against moisture by taking advantage large variety of the available organic ligand, which can promote surface modifications capable to adjust the hydrophilic/hydrophobic properties. Additionally, the photocatalytic activity of these novel perovskite materials has been studied in model reactions in order to confirm their stability under reaction conditions. On the other hand, the photo-assisted nitrogen fixation reaction has been also studied in detail in this Doctoral Thesis. on one hand, new organometallic complexes have been synthetized, characterized and tested as homogeneous photo and electrocatalysts for this reaction. They have been demonstrated to be able to activate dinitrogen molecule under electrochemical cathodic potentials to form ammonia. On the other hand, ruthenium nanoparticles deposited on a titanate-based perovskite material have been prepared and tested as heterogeneous photocatalyst for ammonia production in continuous flow. Moreover, it has been demonstrated that the addition of alkali metals to this photocatalyst can boost the photocatalytic activity of this reaction. Thus, this composite material has demonstrated to be among the most efficient photocatalysts in the current state-of-the art for this reaction, as well as very stable under reaction conditions. Considering the large industrial importance of N2 fixation and the mild conditions of pressure and temperature used in the present study, the results of the photo-assisted N2 hydrogenation to ammonia can have a large impact in the area.
Peng, Y. (2021). Hybrid Lead Perovskites as Photocatalysts and Materials for Photo- and Electrocatalytic N2 Reduction [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171731
TESIS
Compendio
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Books on the topic "Perovskites form"

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Zhang, H. Mesoscopic Structures and Their Effects on High-Tc Superconductivity. Edited by A. V. Narlikar. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780198738169.013.12.

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This article presents the results of model calculations carried out to determine the mesoscopic structural features of high-temperature superconducting (HTS) crystal structures, and especially their characteristic high critical temperature (Tc) and anisotropy. The crystal structure of high-temperature superconductors (HTSc) is unique in having some mesoscopic features. For example, the structures of a majority of cuprite superconductors are comprised of two structural blocks, perovskite and rock salt, stacked along the c-direction. This article calculates the interaction between the perovskite and rock salt blocks in the form of combinative energy in order to elucidate the effects of mesoscopic structures on high-Tc superconductivity. Both X-ray diffraction and Raman spectroscopy show that a ‘fixed triangle’ exists in the samples under investigation. The article also examines the importance of electron–phonon coupling in high-Tc superconductors.
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Book chapters on the topic "Perovskites form"

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Tiwari, Udit, and Sahab Dass. "Moisture Stable Soot Coated Methylammonium Lead Iodide Perovskite Photoelectrodes for Hydrogen Production in Water." In Springer Proceedings in Energy, 141–48. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63916-7_18.

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AbstractMetal halide perovskites have triggered a quantum leap in the photovoltaic technology marked by a humongous improvement in the device performance in a matter of just a few years. Despite their promising optoelectronic properties, their use in the photovoltaic sector remains restricted due to their inherent instability towards moisture. Here, we report a simple, cost-effective and highly efficient protection strategy that enables their use as photoelectrodes for photoelectrochemical hydrogen production while being immersed in water. A uniform coating of candle soot and silica is developed as an efficient hydrophobic coating that protects the perovskite from water while allowing the photogenerated electrons to reach the counter electrode. We achieve remarkable stability with photocurrent density above 1.5 mA cm−2 at 1 V versus saturated calomel electrode (SCE) for ~1 h under constant illumination. These results indicate an efficient route for the development of stable perovskite photoelectrodes for solar water splitting.
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Fujimoto, Shohei, Takemasa Fujiseki, Masato Tamakoshi, Akihiro Nakane, Tetsuhiko Miyadera, Takeshi Sugita, Takurou N. Murakami, Masayuki Chikamatsu, and Hiroyuki Fujiwara. "Organic-Inorganic Hybrid Perovskites." In Spectroscopic Ellipsometry for Photovoltaics, 471–93. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95138-6_10.

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Onishi, Taku. "Perovskites: Application and Structure." In Ferroelectric Perovskites for High-Speed Memory, 19–36. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2669-3_2.

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Shabdan, Erkin, Blake Hanford, Baurzhan Ilyassov, Kadyrzhan Dikhanbayev, and Nurxat Nuraje. "Perovskite Solar Cell." In Multifunctional Nanocomposites for Energy and Environmental Applications, 91–111. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2018. http://dx.doi.org/10.1002/9783527342501.ch5.

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Souza, Felipe M. de, and Ram K. Gupta. "Nanostructured Perovskites for Light-Emitting Diodes." In Nanotechnology for Light Pollution Reduction, 297–314. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003185109-17.

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Onishi, Taku. "Quantum Mechanics." In Ferroelectric Perovskites for High-Speed Memory, 73–83. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2669-3_6.

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Onishi, Taku. "Dielectric." In Ferroelectric Perovskites for High-Speed Memory, 3–17. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2669-3_1.

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Onishi, Taku. "Molecular Orbital Calculation." In Ferroelectric Perovskites for High-Speed Memory, 125–41. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2669-3_10.

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Onishi, Taku. "Ferroelectric." In Ferroelectric Perovskites for High-Speed Memory, 53–62. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2669-3_4.

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Onishi, Taku. "Ferroelectric Materials: History and Present Status." In Ferroelectric Perovskites for High-Speed Memory, 63–70. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2669-3_5.

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Conference papers on the topic "Perovskites form"

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Choy, Wallace, and Jian Mao. "Solution-based and Microfabrication-free Approach to Form Ordered Nanostructured Perovskites for Photovoltaic and LED Applications." In 10th International Conference on Hybrid and Organic Photovoltaics. Valencia: Fundació Scito, 2018. http://dx.doi.org/10.29363/nanoge.hopv.2018.117.

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Parida, Bhaskar, Abdul Kareem Kalathil Soopy, Hiba Shahulhameed, and Adel Najar. "Zn-Porphyrin Blended Anti-Solvent Treatment for Grain Boundary Passivation of Perovskite Solar Cells." In Frontiers in Optics. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/fio.2022.jtu4a.39.

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We report the passivation of FA0.97MA0.03PbI3 perovskites grains by Zn-porphyrin blended anti-solvent treatment. The efficiency was improved to 16.75% because Zn-porphyrin passivated the grain-boundary defects and improved hole transport across the perovskite film.
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Lagerbom, J., A. P. Nikkilä, M. Kylmälahti, P. Vuoristo, U. Kanerva, and T. Varis. "Phase Stability and Structure of Conductive Perovskite Ceramic Coatings by Thermal Spraying." In ITSC2008, edited by B. R. Marple, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and G. Montavon. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 2008. http://dx.doi.org/10.31399/asm.cp.itsc2008p1091.

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Abstract Perovskites are considered as potential materials in solid oxide fuel cells (SOFC) for different reasons at different parts of the fuel cells. Perovskites such as La0.8Sr0.2MnO3 (LSM) and other compositions are electrically conductive which is necessary for SOFC applications. One possible application is protection coating for interconnect plates (bipolar plate) to avoid chromium oxide evaporation from the surface of ferritic stainless steel. Different commercial and experimental perovskite powders were sprayed by plasma and HVOF spraying under different spray conditions. Spraying of pervoskites was found to be challenging and required careful parameter optimization in both spray methods. Microstructure and phase structure of the coatings were investigated. A very fine crack structure, possibly caused by low mechanical strength and low ductility of the compounds, was easily formed in coatings prepared by plasma and HVOF spraying. Spraying method, parameters and spraying atmospheres were found to affect the stability of the perovskite compounds due to low chemical stability at high spray temperatures. Oxygen deficiency or oxygen surplus was concluded to cause distortion of the compounds crystal structure, causing thus shifting of XRD-peaks due to change of lattice parameters. Electric conductivity was affected by the crystal structure.
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Hameed, Areeba, Khulood Logade, Naba Ali, Priya Ghosh, Sadiya Shafath, Sumaiya Salim, Anchu Ashok, Anand Kumar, and Mohd Ali H. Saleh Saad. "Highly active Bifunctional Lamo3 (M=Cr, Mn, Fe, Co, Ni) Perovskites for Oxygen Reduction and Oxygen Evolution Reaction in Alkaline Media." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0106.

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Lanthanum based electrocatalytically active perovskites, LaMO3 (M=Cr, Mn, Fe, Co, Ni), were synthesized using a single step solution combustion synthesis technique. The perovskites showed exceptional performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline medium. Based on the experimental results and literature survey, it is suggested that the exceptional activity of Mn and Co based lanthanum perovskite catalyst could be due to the optimum stabilization of reaction intermediates involved in the rate-determining step (RDS) of ORR/OER. According to crystal field theory (CFT), the d-orbital of transition metals are affected by the octahedral arrangement of six negative charges around it. The d orbital degenerates by splitting into two high energy (eg) and three lower energy orbitals (t2g) while maintaining the same average energy level. The rate-determining step in the ORR/OER reaction that based on the eg orbital filling of B site transition metal cations If the d-electrons are less, the valence state goes up and lowering the eg orbital filling that results in strong adsorption of oxygenated species on the B site (strong B-OH bond). This strong bonding limits the overall reaction rate by the slow desorption of OH and its derivatives during ORR/OER. Similarly, too high eg filling causes weak adsorption of oxygenated species that limits the reaction through the slow adsorption of reactants. Therefore, to enhance the activity of ORR/OER reaction it is required to balance the adsorption and desorption of the reactants and the intermediate respectively. The better way is to optimize the eg orbital filling to be nearly 1 (eg = 1).Based on the experimental results and literature survey, it is suggested that the exceptional activity of Mn and Co based lanthanum perovskite catalyst could be due to the optimum stabilization of reaction intermediates involved in the rate-determining step (RDS) of ORR and OER.
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Jena, Hrudananda, and B. Rambabu. "Effect of Sonochemical, Regenerative Sol Gel and Microwave Assisted Synthesis Techniques on the Formation of Dense Electrolytes and Porus Electrodes for All Perovskite IT-SOFCs." In ASME 2006 4th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2006. http://dx.doi.org/10.1115/fuelcell2006-97262.

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The influence of preparation techniques on the microstructure, grain-size and consequently on the electrical transport properties of the ABO3 structured materials used as electrode and electrolytes in all perovskite IT-SOFC were investigated. Nano-crystalline powders of La1-xMxGa1-yNyO3±δ (M = Sr,; x = −0.10 to 0.15; N = Mg; y = −0.10 to 0.15) (LSGM) as electrolyte, porous La0.8Sr0.2Co0.8Fe0.2O3±δ (LSCF) or LaNi1-xFexO3±δ (x = 0–0.5) (LNF) as cathode, La0.8Sr0.2Cr0.7Mn0.3O3±δ (LSCM) as anode and LaCrO3 or substituted LaCrO 3 as interconnect were synthesized by various wet chemical methods. The wet chemical methods like metal-carboxylate gel decomposition, hydroxide co-precipitation, sonochemical and regenerative sol-gel process followed by microwave sintering of the powders have been used. Microwave sintering parameters were optimized by varying sintering time, and temperature to achieve higher density of LSGM pellets. The phase pure systems were obtained at sintering duration of 30 min at 1200 °C. The XRD, HR-TEM, and SEM measurements revealed the average grain size of these perovskites was ∼ 22 nm range. The electrical conductivities of the compositions were measured by ac (5Hz–13MHz) and dc techniques. The conductivity of the sintered pellets was found to be ∼0.01–0.21 S/cm at 550–1000°C range for electrolyte and 1.5–100 S/cm at 25–1000°C for electrodes respectively. The effect of sonochemical, and regenerative sol-gel methods in processing large quantities of nano-crystalline perovskites with multi-element substitutions at A- and B-sites to achieve physico-chemical compatibility for fabricating zero emission all perovskite IT-SOFCs are reported in this paper.
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Cai, Zhuangli, Zuolin Liu, Bin Yang, Min Yang, and Shangchao Lin. "Diffusion-Mediated Anharmonic Phonon Transport and Thermal Conductivity Reduction in Defective Hybrid Perovskites." In ASME 2021 Heat Transfer Summer Conference collocated with the ASME 2021 15th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/ht2021-62601.

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Abstract Hybrid metal halide perovskite is a promising material for efficient photovoltaic cells and potential thermoelectric energy conversion. This paper investigates phonon thermal transport in iodine-vacancy-defect methylammonium lead iodide (MAPbI3) perovskite using molecular dynamics simulations. The results show that the iodine vacancy defects suppress the thermal conductivity of defective MAPbI3. This effect is enhanced with increasing the defect concentration. The reduction of thermal conductivity of MAPbI3 with iodine vacancy defects compared with the pristine counterpart is mainly attributed to the enhanced phonon anharmonicity and shorter phonon relaxation time due to the phonon-defect scattering. Although iodine diffusion is observed in MAPbI3 with iodine vacancy defects, defect migration has a limited impact on mass-transfer induced convective phonon transport, while it is a source of phonon anharmonicity. This study may provide guidance for theoretical research and industrial application of as-synthesized metal halide perovskites with intrinsic defects.
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Chamarro, M., G. Garcia-Arellano, G. Trippé-Allard, E. Deleporte, F. Bernardot, and C. Testelin. "The coherent spin dynamics in perovskite films: Advantages of Sn-­‐based perovskites against Pb-­‐based perovskites." In Sustainable Metal-halide perovskites for photovoltaics, optoelectronics and photonics. València: FUNDACIO DE LA COMUNITAT VALENCIANA SCITO, 2022. http://dx.doi.org/10.29363/nanoge.sus-mhp.2022.035.

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Khuan, Chzhibin, and Anna Vladimirovna Mitrofanova. "Prospects for obtaining perovskite-like compounds with the Dion-Jacobson structure and the influence of precursors on their phase formation, structure, and properties." In International Research-to-practice conference. TSNS Interaktiv Plus, 2022. http://dx.doi.org/10.21661/r-556864.

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Layered perovskites, including the Dion-Jacobson phases, are of interest to researchers due to a wide range of revealed properties. Among them there are compounds with high photocatalytic activity, ionic conductors, ferroelectrics, piezoelectrics, ferroelectrics and luminophores, as well as materials with unique magnetic properties. However, the properties of these materials largely depend on the method of synthesis and the precursors used, so the study of the possibility of obtaining layered perovskite-like compounds of various compositions remains relevant. The purpose of this work is to study various literature sources, to identify the possibility and methods for obtaining pure phases with the Dion-Jacobson structure, to consider the areas of application of these compounds, and to establish prospects for further research.
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Vagott, Jacob, Carlo Perini, Andres Felipe Castro Mendez, Juanita Hidalgo, Kathryn Bairley, and Juan-Pablo Correa-Baena. "PbI2 and Lead Halide Perovskites by Atomic Layer Deposition for Perovskite Solar Cells." In International Conference on Hybrid and Organic Photovoltaics. València: Fundació Scito, 2022. http://dx.doi.org/10.29363/nanoge.hopv.2022.138.

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Morales-Masis, Monica. "Pulsed Laser Deposition of Lead-free Halide Perovskites and Double Perovskites." In Materials for Sustainable Development Conference (MAT-SUS). València: FUNDACIO DE LA COMUNITAT VALENCIANA SCITO, 2022. http://dx.doi.org/10.29363/nanoge.nfm.2022.121.

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Reports on the topic "Perovskites form"

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Gur, Ilan. Wide Band-Gap Perovskites for Tandem Photovoltaics. Office of Scientific and Technical Information (OSTI), April 2020. http://dx.doi.org/10.2172/1607930.

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McGehee, Michael, and Tonio Buonassisi. Perovskite Solar Cells for High-Efficiency Tandems. Office of Scientific and Technical Information (OSTI), September 2017. http://dx.doi.org/10.2172/1420976.

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Xu, Tao, and Kai Zhu. On-Device Lead Detention for Perovskite Solar Cells. Office of Scientific and Technical Information (OSTI), July 2021. http://dx.doi.org/10.2172/1830665.

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Rambabu Bobba. Dense Membranes for Anode Supported all Perovskite IT-SOFCs. Office of Scientific and Technical Information (OSTI), September 2006. http://dx.doi.org/10.2172/902844.

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Rambabu Bobba. Dense Membranes for Anode Supported all Perovskite IT-SOFCs. Office of Scientific and Technical Information (OSTI), September 2007. http://dx.doi.org/10.2172/937594.

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McNamara, Joy, and Kaitlin Lawrence. Novel Perovskite Semiconductors for the Detection of Special Nuclear Material. Office of Scientific and Technical Information (OSTI), August 2020. http://dx.doi.org/10.2172/1651113.

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Lawrence, K. NOVEL PEROVSKITE SEMICONDUCTORS FOR THE DETECTION OF SPECIAL NUCLEAR MATERIAL. Office of Scientific and Technical Information (OSTI), September 2019. http://dx.doi.org/10.2172/1569632.

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Rutstrom, Daniel, Mariya Zhuravleva, and Kenneth Mcclellan. Evaluating New Double Perovskite Halide Scintillators for Radiation Detection Applications. Office of Scientific and Technical Information (OSTI), August 2021. http://dx.doi.org/10.2172/1813814.

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Mao, Zhiqiang. Searching for Exotic Bulk and Interfacial Quantum Phenomena of Perovskite Ruthenates. Fort Belvoir, VA: Defense Technical Information Center, March 2010. http://dx.doi.org/10.21236/ada534042.

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Sarney, Wendy L., Kimberley A. Olver, John W. Little, Frank E. Livingston, Krisztian Niesz, and Daniel E. Morse. Materials Research of Perovskite Thin Films for Uncooled Infrared (IR) Detectors. Fort Belvoir, VA: Defense Technical Information Center, July 2011. http://dx.doi.org/10.21236/ada548946.

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