Synthesis Of Perovskite Research Articles

Synthesis and High-pressure Properties of (Nd0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 High-entropy Perovskite

The recent development of high-entropy perovskites has demonstrated their tremendous promise for various applications. To meet the expanding needs for extreme environment applications, however, the critical properties of high-entropy perovskite at high pressure remain to be disclosed. In the present work, an A-site high-entropy perovskite (Nd0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 was synthesized. High-pressure investment on the phase stability, dielectric properties, and bandgap was conducted using diamond anvil cell combined with comprehensive in-situ measurements. The results reveal that (Nd0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 remains the perovskite structure at the pressure up to ~15GPa. The grain resistance exhibits an exponential decrease with the increasing pressure, whilst an unusual change of the grain boundary resistance was observed at ~7GPa. Furthermore, (Nd0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 shows a slight increase of the bandgap upon compression. Our multifaceted approach provides a comprehensive understanding of the high-pressure behavior of high-entropy perovskite, offering valuable insights for the design and optimization of advanced functional materials for high-pressure environments.

Regulating Second‐Harmonic Generation in 2D Chiral Perovskites Through Achiral Organic Spacer Cation Alloying Strategy

AbstractThe inherent structural flexibility and chiroptical activity of 2D chiral perovskites make them promising for the nonlinear optical (NLO) application. A comprehensive understanding of the second‐harmonic generation (SHG) mechanism in 2D chiral perovskites is essential for developing NLO devices. However, the rational design of 2D chiral perovskite structures to regulate SHG properties remains challenging. Herein, to regulate SHG response, an achiral organic spacer cation alloying strategy is employed to construct a series of 2D chiral perovskites. Through the measurement of temperature‐dependent photoluminescence (PL) spectra, it is revealed that the material design strategy can effectively modulating self‐trapped exciton (STE) emission. More importantly, it is confirmed that there is a competitive relationship between STE emission and SHG in 2D chiral perovskites. Meanwhile, the microscopic imaging of circularly polarized‐SHG is demonstrated in chiral perovskites. This work will not only advance the understanding of the SHG mechanism in 2D chiral perovskites but also provide inspiration for the rational design and synthesis of perovskites for NLO devices.

Formamidinium Incorporates into Rb-based Non-Perovskite Phases in Solar Cell Formulations.

Organic-inorganic hybrid perovskite materials, such as formamidinium lead iodide (FAPbI3), are among the most promising emerging photovoltaic materials. However, the spontaneous phase transition from the photoactive perovskite phase to an inactive non-perovskite phase complicates the application of FAPbI3 in solar cells. To remedy this, alkali metal cations, most often Cs+, Rb+ or K+, are included during perovskite synthesis to stabilize the photoactive phase. The atomic-level mechanisms of stabilization are complex. While Cs+ dopes directly into the perovskite lattice, Rb+ does not, but instead forms an additional non-perovskite phase, and the mechanism by which Rb confers increased stability remains unclear. Here, we use 1H-87Rb double resonance NMR experiments to show that FA+ incorporates into the Rb-based non-perovskite phases (FAyRb1-yPb2Br5 and δ-FAyRb1-yPbI3) for both bromide and iodide perovskite formulations. This is demonstrated by changes in the 1H and 87Rb chemical shifts, 1H-87Rb heteronuclear correlation spectra, and 87Rb{1H} REDOR spectra. Simulation of the REDOR dephasing curves suggests up to ~60 % FA+ incorporation into the inorganic Rb-based phase for the bromide system. In light of these results, we hypothesize that the substitution of FA+ into the non-perovskite phase may contribute to the greater stability conferred by Rb salts in the synthesis of FA-based perovskites.

Formamidinium Incorporates into Rb‐based Non‐Perovskite Phases in Solar Cell Formulations

AbstractOrganic‐inorganic hybrid perovskite materials, such as formamidinium lead iodide (FAPbI3), are among the most promising emerging photovoltaic materials. However, the spontaneous phase transition from the photoactive perovskite phase to an inactive non‐perovskite phase complicates the application of FAPbI3 in solar cells. To remedy this, alkali metal cations, most often Cs+, Rb+ or K+, are included during perovskite synthesis to stabilize the photoactive phase. The atomic‐level mechanisms of stabilization are complex. While Cs+ dopes directly into the perovskite lattice, Rb+ does not, but instead forms an additional non‐perovskite phase, and the mechanism by which Rb confers increased stability remains unclear. Here, we use 1H−87Rb double resonance NMR experiments to show that FA+ incorporates into the Rb‐based non‐perovskite phases (FAyRb1‐yPb2Br5 and δ‐FAyRb1‐yPbI3) for both bromide and iodide perovskite formulations. This is demonstrated by changes in the 1H and 87Rb chemical shifts, 1H−87Rb heteronuclear correlation spectra, and 87Rb{1H} REDOR spectra. Simulation of the REDOR dephasing curves suggests up to ~60 % FA+ incorporation into the inorganic Rb‐based phase for the bromide system. In light of these results, we hypothesize that the substitution of FA+ into the non‐perovskite phase may contribute to the greater stability conferred by Rb salts in the synthesis of FA‐based perovskites.

Optimization of CsPbBr3/PVDF composite for enhanced UV photodetection application.

Halide perovskites have exhibited great research impact for developing innovative materials with novel properties. Here, we report the synthesis of different caesium lead bromide perovskites using different (Cs/Pb) molar ratios and fabrication of their corresponding perovskite/polyvinylidene fluoride (PVDF) composites, as well as study of their structural and UV-photodetection properties. Spin-coated perovskite/PVDF composite thin films revealed strong oriented XRD diffraction peaks along the c-axis direction (00l) with homogeneously distributed perovskite microcrystals in the polymer matrix. The high-Cs containing perovskite/PVDF composite, with Cs/Pb (3/1) molar ratio, demonstrated the highest green emission under UV light and its corresponding UV-photodetector exhibited the highest UV photo-responsivity. These results highlight the importance of structural modulation and additive manufacturing for tailoring the optoelectronic properties of halide perovskites.

Facile combustion synthesis of Granular-like La1-xSrxMnO3 Perovskites as electrode material for supercapacitor application

This study focuses on synthesizing a series of perovskite-type La1-xSrxMnO3 materials using a solution combustion method to investigate the impact of varying concentrations of La and Sr. The samples were prepared with different La and Sr concentrations (La1-xSrxMnO3, X = 0, 0.2, 0.4, 0.6, and 0.8) and labeled as LSMO-2 (La0.8Sr0.2MnO3), LSMO-3 (La0.6Sr0.4MnO3), LSMO-4 (La0.4Sr0.6MnO3), LSMO-5 (La0.2Sr0.8MnO3. The structural, morphological, and compositional characteristics of the synthesized electrodes were thoroughly analyzed. X-ray diffraction (XRD) confirmed the formation of a rhombohedral structure with an R-3c space group, while Fourier-transform infrared spectroscopy (FT-IR) verified the presence of all functional groups in the samples. Field emission scanning electron microscopy (FE-SEM) revealed a cluster of nanopowder morphology, and compositional analysis further validated the formation of the prepared samples. The electrodes were then screen-printed onto Ni-foam and evaluated for their electrochemical performance. Notably, the La1-xSrxMnO3 electrode demonstrated a high specific capacitance of 1271.5 F/g at a current density of 10 mA/cm2 and maintained 83.45 % cyclic stability after 10,000 cycles. Moreover, the power law was employed to investigate the charge storage mechanism of the LMSO-4 electrode. To assess the practical application potential of the La1-xSrxMnO3 electrode, a solid-state supercapacitor device was fabricated, and its performance was investigated. The device achieved a maximum specific capacitance of 206 F/g at 5 mA, with an energy density of 16 Wh/kg and a power density of 2400 W/kg, retaining 94 % of its performance after 5000 cycles. Overall, La1-xSrxMnO3 electrodes show great promise as materials for supercapacitor applications due to their impressive electrochemical properties.

Confined Flash Printing and Synthesis of Stable Perovskite Nanofilms under Ambient Conditions.

The fabrication of stable perovskite nanofilm patterns is important for the development of functional optical devices. However, current production approaches are limited by the requirement for strict inert gas protection and long processing times. Here, a confined flash printing synthesis method is presented to generate perovskite nanofilms under ambient conditions, combining precursor transfer, perovskite synthesis, crystallization, and polymer protection in a single step within milliseconds. A laser simultaneously prints and induces the flash synthesis, confined in a polymer nanofilm, under normal ambient conditions. Due to its simplicity and flexibility, the method enables the combination and screening of many different perovskite precursor materials on various substrates. Besides for the development of novel perovskite materials and devices, the nanofilms can be applied for biodetection. The unique H2O2-responsive property of the ultrathin perovskite quantum dot film is applied for biomolecule detection based on oxidase-catalyzed enzymatic reactions.

Microwave-assisted in-situ synthesis of low-dimensional perovskites within metal-organic frameworks for optoelectronic applications

Halide perovskites are renowned for their remarkable optoelectronic properties, yet their application is hindered by stability challenges. Metal-organic frameworks (MOFs) have emerged as promising matrices for enhancing perovskite durability. In this study, we achieved the in-situ synthesis of a series of perovskites within the MOF-5 matrix, spanning three-dimensional, quasi two-dimensional, and two-dimensional structures, via microwave-assisted reaction techniques. This microwave synthesis method has proven to be a rapid and efficient approach for the high-yield production of perovskite materials. These MOF-5⊃perovskites exhibited superior optical properties, positioning them as promising candidates for various optoelectronic applications, including white light-emitting diodes and optical wireless communication (OWC) systems. Significantly, our perovskites demonstrated high and consistent communication rates, making them suitable for both space and underwater OWC deployments. Overall, our study underscores the potential of microwave-assisted synthesis in advancing high-performance perovskite materials, offering valuable insights for the development of future optoelectronic devices.

Terbium- and samarium-doped Li2ZrO3 perovskite materials as efficient and stable electrocatalysts for alkaline hydrogen evolution reactions

The preparation of highly active, rare earth, non-platinum-based catalysts for hydrogen evolution reactions (HER) in alkaline solutions would be useful in realizing green hydrogen production technology. Perovskite oxides are generally regarded as low-active HER catalysts, owing to their unsuitable hydrogen adsorption and water dissociation. In this article, we report on the synthesis of Li2ZrO3 perovskites substituted with samarium and terbium cations at A-sites for the HER. LSmZrO3 (LSmZO) and LTbZrO3 (LTbZO) perovskite oxides are more affordable materials, starting materials in abundance, environmentally friendly due to reduced usage of precious metal and moreover have potential for several sustainable synthesis methods compared to commercial Pt/C. The surface and elemental composition of the prepared materials have been confirmed by X-ray photoelectron spectroscopy (XPS). The morphology and composition analyses of the LSmZO and LTbZO catalysts showed spherical and regular particles, respectively. The electrochemical measurements were used to study the catalytic performance of the prepared catalyst for hydrogen evolution reactions in an alkaline solution. LTbZO generated 2.52 mmol/g/h hydrogen, whereas LSmZO produced 3.34 mmol/g/h hydrogen using chronoamperometry. This was supported by the fact that the HER electrocatalysts exhibited a Tafel slope of less than 120 mV/dec in a 1.0 M alkaline solution. A current density of 10 mA/cm2 is achieved at a potential of less than 505 mV. The hydrogen production rate of LTbZO was only 58.55%, whereas LSmZO had a higher Faradaic efficiency of 97.65%. The EIS results demonstrated that HER was highly beneficial to both electrocatalysts due to the relatively small charge transfer resistance and higher capacitance values.

Optimizing Methylammonium Lead Iodide Perovskite Synthesis for Solar Cells via Two-step Spin Coating with Mixed Solvents

Optimizing Methylammonium Lead Iodide Perovskite Synthesis for Solar Cells via Two-step Spin Coating with Mixed Solvents

(Invited) From PL-Inactive to PL-Active: Synthesis and Properties of Novel PL-Active 2D Lead-Free Double Perovskites Based on (PA)4AgInBr8

In this work, novel two-dimensional lead-free double perovskites ((R)4MaMbMcX8, a+b+c=2) were synthesized to achieve novel compositional and dimensional tunability. Specifically, manganese (Mn2+) is incorporated into (PA)4AgInBr8 (PA = CH3(CH2)2NH3+) to form (PA)4Ag1-0.5xMnxIn1-0.5xBr8 (0 ≤ x ≤ 1). These samples were tuned to be PL-emissive under room temperature via this manganese alloying strategy. Three emission pathways can be investigated: band edge emission, emission stemming from self-trapped excitons, and the energy transfer processes associated with Mn2+ center energy levels. Temperature-dependent PL elucidates two emissive modes: self-trapped exciton emission as well as Mn-center emission based on analysis of the associated Huang-Rhys factors. Overall, this work informs the development of additional light-emissive 2D lead-free double perovskites.

Chiral Perovskite Heterostructure Films of CsPbBr3 Quantum Dots and 2D Chiral Perovskite with Circularly Polarized Luminescence Performance and Energy Transfer.

This work reports the synthesis of chiral perovskite heterostructure films by combining a two-dimensional (2D) chiral (R-/S-MBA)2PbI4 perovskite with CsPbBr3 quantum dots (QDs). The as-synthesized chiral heterostructure films exhibit obvious circularly polarized luminescence (CPL) properties, even though pure 2D chiral perovskite cannot present photoluminescence. It indicates that the chirality of the excited state of the QDs originates from the 2D chiral perovskite. The circular polarization-resolved transient absorption (TA) spectra further demonstrate that the CPL response of heterostructure films originates from the energy transfer between the chiral perovskite layer and QDs layer and the suppression of spin relaxation, which induces the imbalance of the spin population of excited states in QDs layer. In addition, the photoluminescence (PL), circular dichroism (CD), and CPL spectra of these heterostructure films can be controlled by varying the thickness and component of the chiral perovskite layer, which demonstrates that the anion exchange between chiral perovskite and CsPbBr3 QDs can tune the chemical composition and optoelectronic properties due to the low bonding energy difference between them and decrease the strain within the QDs layer to reduce the radiative recombination lifetime. This work provides guidance for the synthesis of chiral perovskites with a strong CPL response and further provides insight into the origination of CPL.

Inorganic Salt Solution Assisted Grinding Synthesis of Stimuli-Responsive Perovskites for Reversible Information Encryption and Decryption Based on I Ching 64 Hexagrams

Inorganic Salt Solution Assisted Grinding Synthesis of Stimuli-Responsive Perovskites for Reversible Information Encryption and Decryption Based on I Ching 64 Hexagrams

Crystal structure and Hirshfeld surface analysis of 2-bromo-ethyl-ammonium bromide - a possible side product upon synthesis of hybrid perovskites.

This study presents the synthesis, characterization and Hirshfeld surface analysis of a small organic ammonium salt, C2H7BrN+·Br-. Small cations like the one in the title compound are considered promising components of hybrid perovskites, crucial for optoelectronic and photovoltaic applications. While the incorporation of this organic cation into various hybrid perovskite structures has been explored, its halide salt counterpart remains largely uninvestigated. The obtained structural results are valuable for the synthesis and phase analysis of hybrid perovskites. The title compound crystallizes in the solvent-free form in the centrosymmetric monoclinic space group P21/c, featuring one organic cation and one bromide anion in its asymmetric unit, with a torsion angle of -64.8 (2)° between the ammonium group and the bromine substituent, positioned in a gauche conformation. The crystal packing is predominantly governed by Br⋯H inter-actions, which constitute 62.6% of the overall close atom contacts.

Synthesis, Characterization, Magnetic, Elastic, and Electronic Properties of La2ZnMnO6 Double Perovskite

Synthesis, Characterization, Magnetic, Elastic, and Electronic Properties of La2ZnMnO6 Double Perovskite

Synthesis, characterization, and comparative study of titanium dioxide and methyl ammonium lead iodide perovskite doped with cesium

Synthesis, characterization, and comparative study of titanium dioxide and methyl ammonium lead iodide perovskite doped with cesium

Advances in chalcogenide perovskites: Fundamentals and applications

Chalcogenide perovskites are a family of compounds related to perovskite structures or compositions, which have witnessed rapid advances in recent years. They possess favorable properties such as high stability, low toxicity, direct band gaps, good carrier transport abilities, strong light absorption, and potential luminescent properties, making them stand out in emerging applications, such as photovoltaics, photodetectors, light-emitting devices, and photocatalysts, among others. In this review, we aim to provide a comprehensive overview of the properties, synthesis, and applications of chalcogenide perovskites. First, we first survey the reported material structures/compositions and current understanding of their structural/optical/electrical properties, mechanics, magnetics, and stabilities. Furthermore, we discuss the synthesis strategies of these materials covering various material types such as powders, pellets, thin films, nanocrystals, and single crystals, with a focus on their potential applications, including photovoltaics, photodetectors, and other devices. Finally, we outline a brief conclusion and some prospects for the further research of chalcogenide perovskites, thus promoting more studies and developments in this field. This review can provide new insights into the fundamental properties and potential applications of chalcogenide perovskites, and thereby facilitating their further studies and developments.

Solution combustion synthesis of CaZrO3 ceramic perovskite using different fuels: In-situ FT-IR studies and monitoring of the flame reaction by thermocouple

In this study, nanoparticles of perovskiteCaZrO3 were prepared by a solution combustion technique using urea, glycine, β-alanineand citric acid as fuels. The aim of this work is to estimate the effect of these different fuels on the structure and microstructure of CaZrO3 powders. The flame reaction was estimated by means of a thermocouple which allowed us to show that the combustion reaction velocity. The thermal decomposition of nitrate precursors was studied with the help of TG-DTA coupled with the infrared spectroscopy. The FT-IR spectroscopy enabled to check the identity of the evolved gases over the mass loss process. CaZrO3 powders were calcined at 900 °C for 1 h. The powders were thoroughly characterized by scanning electron microscopy, X-ray diffraction andThermodilatometry. Also, the combustion process using glycine as fuel is beneficial to produce CaZrO3 powders at low temperature, which are known to have a good reactivity with fine particles.

Synthesis, characterisation and voltammetric study of dimethylammonium lead iodide perovskite

In the last decade, the most investigated perovskite materials are the hybrid organic-inorganic perovskites (HOIPs) due to their optoelectronic properties and possible application in the production of photovoltaics. This interest has led to an ongoing search for new HOIP variants, alongside thorough investigations of the properties of existing HOIPs. That is why our research in the field of organic-inorganic perovskites is aimed at the synthesis, characterization, and investigation of the electrochemical properties of dimethylammonium lead iodide (DMAPbI3) using voltammetric studies. A modified synthesis of DMAPbI3, differing slightly from the one described in the literature, was performed by combining stoichiometric amounts of lead iodide (PbI2) and dimethylammonium iodide (DMAI) dissolved in acetonitrile. After conducting controlled evaporation, a yellow crystalline powder of DMAPbI3 was obtained. The identity and purity of the obtained compound were confirmed by powder X-ray diffraction (PXRD), infrared (IR) and Raman spectroscopy, and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). Investigations on the electrochemical properties of DMAPbI3 by cyclic voltammetry were performed with dichloromethane (DCM) and tetrabutylammonium chloride (TBAC) as the electrolyte. A paraffin-impregnated graphite electrode (PIGE) was used as a working electrode, on which the perovskite microparticles were immobilized. The electrochemical activity of DMAPbI3 is recognized through an intense, broad, and irreversible anodic peak attributed to the oxidation of the constituents to different possible products and the decomposition of the perovskite structure.

Synthesis and properties of rare-earth high-entropy perovskite

Synthesis and properties of rare-earth high-entropy perovskite