Chloride Perovskite Research Articles

Frist Principles Study of elastic and acoustic properties of new Chloride Perovskites

Frist Principles Study of elastic and acoustic properties of new Chloride Perovskites

Fine-tuning Cesium lead chloride perovskite field-effect transistors for sensing applications: Bridging numerical modeling and experimental validation

This study presents a comprehensive approach to fine-tuning Cesium Lead Chloride Perovskite Field-Effect Transistors (CsPbCl3-FETs) for sensing applications by bridging numerical modeling with experimental validation. By combining finite element methods in COMSOL Multiphysics for optimization, we tailored FET parameters such as oxide and perovskite thin film thickness. The fabricated FET, with a 200 nm semiconductor layer and 30 nm oxide thickness, was strategically chosen to operate in a non-depletion mode, maximizing mobility while minimizing power consumption. Experimental results closely aligned with numerical simulations, showcasing a threshold voltage of 0.50 V±0.07 V and an impressive on/off current ratio of 1.50 x 104 ± 0.3 x 104. Notably, the perovskite FET exhibited remarkable carrier mobility in saturation mode, reaching 5.40 cm2/V-s ± 0.8 cm2/V-s, outperforming other attempts in the literature. This work underscores the potential of CsPbCl3 FETs for high-performance sensing applications, offering insights into optimizing device parameters for enhanced functionality and efficiency.

Potential Water Collection From Air by Chloride Perovskites.

Directly capturing water from the air has become a compelling strategy to secure water resources. Yet, challenges persist with sorption-based hygroscopic materials, such as inadequate water adsorption efficiency, material degradation post-adsorption, and the need for energy input during water collection. This study introduces an alternative category of sorbent materials potentially for atmospheric water harvesting-metal chloride perovskites-that exhibit spontaneous water vapor adsorption and liquid water collection. This water uptake capability stems from the uncoordinated polar ions that form hydrogen bonds with water molecules, while the cubic lattice imparts a solid framework ensuring structural stability and inhibiting hydrolysis. The methylammonium lead chloride perovskite pellets exhibit efficient water collection performance, with a record absorption rate of 0.841 L m-2 h-1 and a total water collection of 3.675 L m-2 within a 7-h cycle. This initiative attempts to provide a new material class candidate for the potential application of passive atmospheric water harvesting.

Effect of Cation Incorporation on the Structural Distortions and Phase Transitions in Mixed Lead Chloride Perovskite Single Crystals

Effect of Cation Incorporation on the Structural Distortions and Phase Transitions in Mixed Lead Chloride Perovskite Single Crystals

Lead-free Ce-doped perovskite scintillators with high figure of merit

Lead halide perovskite scintillators have recently received extensive research attention owing to their short fluorescence lifetimes, low detection limits, and ease of fabrication compared to traditional scintillators. The nontoxic cerium-doped lead-free perovskites with intrinsically efficient and short lifetime d–f transitions are a prospective replacement for the toxic Pb2+. Here, we demonstrated Ce-doped cesium lanthanide chloride perovskites (Cs3LnCl6, Ln = Gd, Y, Lu) synthesized through a facile solution method for the first time. These perovskites exhibit blue-violet emission, which arises from Ce 5d → 4f transitions. Among three types of Cs3LnCl6 perovskites, Ce:Cs3LuCl6 exhibited high photoluminescence quantum yield (PLQY) of 82% and a short excited-state lifetime of approximately 34 ns. When utilized as X-ray scintillators, Ce:Cs3LuCl6 crystals display a high light yield of 8120 photons per MeV and a low detection limit of 36.8 nGy air s−1. Importantly, the figure of merit (FoM), representing the ratio of light yield to decay time, reaches 239, which is the highest reported value for lead-free perovskite scintillators up to now. Additionally, the fabrication of perovskite/PMMA films was undertaken for practical demonstrations in X-ray imaging, resulting in the attainment of a resolution of up to 8.38 lp/mm. We anticipate that this work will inspire the utilization of Ce-doped Cs3LnCl6 perovskites in ultrafast scintillation applications such as high-energy physics, nuclear reaction monitoring, and dynamic X-ray imaging.

Hexagonal Halide Perovskite Cs2LiInCl6: Cation Ordering, Face-Shared Octahedral Trimers and Mn2+ Luminescence.

The In-based double perovskite halides have been widely studied for promising optical-electric applications. The halide hexagonal perovskite Cs2LiInCl6 was isolated using solid-state reactions and investigated using X-ray diffraction and solid-state NMR spectra. The material adopts a 12-layered hexagonal structure (12R) consisting of layered cationic orders driven by the cationic charge difference and has Li+ cations in the terminal site and In3+ in the central site of face-shared octahedron trimers. Such a cationic ordering pattern is stabilized by electrostatic repulsions between the next-nearest neighboring cations in the trimers. The LiCl6 octahedron displays large distortion and is confirmed by 7Li SSNMR in the Cs2LiInCl6. The Cs2LiInCl6 material has a direct bandgap of ~4.98 eV. The Cs2LiInCl6: Mn2+ displays redshift luminescence (centered at ~610-622 nm) from the substituted Mn2+ emission in octahedron with larger PLQY (17.8 %-48 %) compared with that of Cs2NaInCl6: Mn2+. The Mn-doped materials show luminescent concentration quenching and thermal quenching. The composition Cs2Li0.99In0.99Mn0.02Cl6 exhibits the highest PL intensity, a maximum PLQY of 48 %, and high luminescent retention rate of ~86 % below 400 K and is suitable for application for pc-LED. These findings contribute to our understanding of the chloride perovskites and hold potential for widespread optical applications.

The Effect of Cesium Incorporation on the Vibrational and Elastic Properties of Methylammonium Lead Chloride Perovskite Single Crystals.

Hybrid organic-inorganic lead halide perovskites (LHPs) have emerged as a highly significant class of materials due to their tunable and adaptable properties, which make them suitable for a wide range of applications. One of the strategies for tuning and optimizing LHP-based devices is the substitution of cations and/or anions in LHPs. The impact of Cs substitution at the A site on the structural, vibrational, and elastic properties of MAxCs1-xPbCl3-mixed single crystals was investigated using X-ray diffraction (XRD) and Raman and Brillouin light scattering techniques. The XRD results confirmed the successful synthesis of impurity-free single crystals, which exhibited a phase coexistence of dominant cubic and minor orthorhombic symmetries. Raman spectroscopy was used to analyze the vibrational modes associated with the PbCl6 octahedra and the A-site cation movements, thereby revealing the influence of cesium incorporation on the lattice dynamics. Brillouin spectroscopy was employed to investigate the changes in elastic properties resulting from the Cs substitution. The incorporation of Cs cations induced lattice distortions within the inorganic framework, disrupting the hydrogen bonding between the MA cations and PbCl6 octahedra, which in turn affected the elastic constants and the sound velocities. The substitution of the MA cations with smaller Cs cations resulted in a stiffer lattice structure, with the two elastic constants increasing up to a Cs content of 30%. The current findings facilitate a fundamental understanding of mixed lead chloride perovskite materials, providing valuable insights into their structural and vibrational properties.

A Versatile Synthesis Platform Based on Polymer Cubosomes for a Library of Highly Ordered Nanoporous Metal Oxides Particles.

Polymer cubosomes (PCs) have well-defined inverse bicontinuous cubic mesophases formed by amphiphilic block copolymer bilayers. The open hydrophilic channels, large periods, and robust physical properties of PCs are advantageous to many host-guest interactions and yet not fully exploited, especially in the fields of functional nanomaterials. Here, the self-assembly of poly(ethylene oxide)-block-polystyrene block copolymers is systematically investigated and a series of robust PCs is developed via a cosolvent method. Ordered nanoporous metal oxide particles are obtained by selectively filling the hydrophilic channels of PCs via an impregnation strategy, followed by a two-step thermal treatment. Based on this versatile PC platform, the general synthesis of a library of ordered porous particles with different pore structures , tunable large pore size (18-78nm), high specific surface areas (up to 123.3m2g-1 for WO3) and diverse framework compositions, such as transition and non-transition metal oxides, rare earth chloride oxides, perovskite, pyrochlore, and high-entropy metal oxides is demonstrated. As typical materials obtained via this method, ordered porous WO3 particles have the advantages of open continuous structure and semiconducting properties, thus showing superior gas sensing performances toward hydrogen sulfide.

Revealing the Emission Mechanism in Sb3+-Doped All-Inorganic Cadmium Chloride Perovskite

Revealing the Emission Mechanism in Sb³⁺-Doped All-Inorganic Cadmium Chloride Perovskite

Stereochemically Active Lone Pair Leads to Birefringence in the Vacancy Ordered Cs3Sb2Cl9 Perovskite Single Crystals.

Stereochemically active lone pair (SCALP) cations are attractive units for realizing optical anisotropy. Antimony(III) chloride perovskites with the SCALP have remained largely unknown to date. We synthesized a new vacancy ordered Cs3Sb2Cl9 perovskite single crystals with SbCl6 octahedral linkage containing the SCALP. Remarkably, all-inorganic halide perovskite Cs3Sb2Cl9 single crystals exhibit an exceptional birefringence of 0.12 ± 0.01 at 550 nm. The SCALP brings a large local structural distortion of the SbCl6 octahedra promoting birefringence optical responses in Cs3Sb2Cl9 single crystals. Theoretical calculations reveal that the considerable hybridization of Sb 5s and 5p with Cl 3p states largely contribute to the SCALP. Furthermore, the change in the Sb-Cl-Sb bond angle creates distortion in the SbCl6 octahedral arrangement in the apical and equatorial directions within the crystal structure incorporating the required anisotropy for the birefringence. This work explores pristine inorganic halide perovskite single crystals as a potential birefringent material with prospects in integrated optical devices.

Narrowing band gap and enhanced optoelectronic properties in methylammonium lead chloride perovskite under pressure

In this study, we explore the impact of hydrostatic pressure on the structural stability, elastic properties, mechanical behavior, thermodynamics, and optoelectronic characteristics of lead halide perovskite, specifically focusing on CH3NH3PbCl3. Through high-level ab initio simulation techniques, we investigate the lattice squeezing effects on this methylammonium lead chloride perovskite. Our findings reveal that applying hydrostatic pressure squeezes lattice parameters, influences the electronic profile, and results in spin-split band edges. The band gaps in compressed perovskites are observed to be narrower, with the potential for pressure-induced closures, offering new electronic features under various thermodynamic conditions. Because of the high-quality crystal and its optimal optical band gap, we successfully construct an efficient UV-photodetector, highlighting its promising applications in optoelectronics. This work contributes to a deeper atomistic understanding of inorganic halide perovskite behavior under external pressure and demonstrates the potential for realizing enhanced electronic functionalities through pressure conditions.

Composition dependence of X-ray stability and degradation mechanisms at lead halide perovskite single crystal surfaces.

The multiple applications of lead halide perovskite materials and the extensive use of X-ray based techniques to characterize them highlight a need to understand their stability under X-ray irradiation. Here, we present a study where the X-ray stability of five different lead halide perovskite compositions (MAPbI3, MAPbCl3, MAPbBr3, FAPbBr3, CsPbBr3) was investigated using photoelectron spectroscopy. To exclude effects of thin film formation on the observed degradation behaviors, we studied clean surfaces of single crystals. Different X-ray resistance and degradation mechanisms were observed depending on the crystal composition. Overall, perovskites based on the MA+ cation were found to be less stable than those based on FA+ or Cs+. Metallic lead formed most easily in the chloride perovskite, followed by bromide, and only very little metallic lead formation was observed for MAPbI3. MAPbI3 showed one main degradation process, which was the radiolysis of MAI. Multiple simultaneous degradation processes were identified for the bromide compositions. These processes include ion migration towards the perovskite surface and the formation of volatile and solid products in addition to metallic lead. Lastly, CsBr formed as a solid degradation product on the surface of CsPbBr3.

Six Metal Cations in One Double Perovskite: Exploring Complexity of Chloride Elpasolites by High-Throughput Experimentation

A high-throughput screening of lead-free double chloride perovskites Cs2MIMIIICl6 is performed combining combinatorial robot-assisted synthesis with accelerated structural and spectral characterizations. The screening encompasses about 350 elpasolite compounds with broad...

Experimentally verified analytical models for the dynamic response of perovskite solar cells using measured I–V and C–V characteristics

Perovskite solar cells (PSC) have gained significant attention recently due to their high efficiency and potential for low-cost fabrication. Understanding the dynamic behavior of these cells is crucial for optimizing their performance and stability. In this paper, we propose experimentally verified analytical models for the dynamic response of perovskite solar cells. The models are developed based on the measured current–voltage (I-V) and capacitance–voltage (C-V) characteristics obtained from experiments. The study introduces the first fully analytical model for the dynamic response of perovskite solar cells, considering single, double, and triple diode models with three polynomials C-V fitting functions. The analytical models are fed by experimental measured data and coefficients and pot-processed by an equilibrium optimizer. The proposed methodology was investigated using five batches of cesium lead chloride perovskite solar cells, with a power conversion efficiency of around 16.35% ± 0.32%. The suggested analytical model with an equilibrium optimizer showed a significant capability to predict the cell circuit parameters with a root-mean-square error below 0.00103, as the minimum error recorded so far in PSCs.

Size effects on polaron formation in lead chloride perovskite thin films

Lead halide perovskites (LHP) are of interest for light-emitting applications due to the tunability of their bandgap across the visible and near-infrared spectrum (IR) coupled with efficient photoluminescence quantum yields (PLQY). It is widely speculated that photoexcited electrons and holes spatially separate into large negative (electron) and positive (hole) polarons. Polarons are expected to be optically active. With the observed optoelectronic signatures expecting to show potential excited states within the polaronic potential well. From the polaron excited-state we predict that large polarons should be capable of spontaneous emission, photoluminescence, in the mid-IR to far-IR regime based on the concept of inverse occupations within the polaron potential well. Here we use density functional theory (DFT), including spin–orbit coupling interactions, for calculations on a two-dimensional Dion-Jacobson (DJ) lead chloride perovskite atomistic model of various sizes as a host material for either negative or positive polarons to examine the effects of size on polaron formation. This work provides computational evidence that polaron formation through selective charge injection does not show the same level of localisation for positive and negative polarons.

The Effect of Cation Incorporation on the Elastic and Vibrational Properties of Mixed Lead Chloride Perovskite Single Crystals

In recent years, there have been intense studies on hybrid organic–inorganic compounds (HOIPs) due to their tunable and adaptable features. This present study reports the vibrational, structural, and elastic properties of mixed halide single crystals of MAxFA1-xPbCl3 at room temperature by introducing the FA cation at the A-site of the perovskite crystal structure. Powder X-ray diffraction analysis confirmed that its cubic crystal symmetry is similar to that of MAPbCl3 and FAPbCl3 with no secondary phases, indicating a successful synthesis of the MAxFA1-xPbCl3 mixed halide single crystals. Structural analysis confirmed that the FA substitution increases the lattice constant with increasing FA concentration. Raman spectroscopy provided insight into the vibrational modes, revealing the successful incorporation of the FA cation into the system. Brillouin spectroscopy was used to investigate the changes in the elastic properties induced via the FA substitution. A monotonic decrease in the sound velocity and the elastic constant suggests that the incorporation of large FA cations causes distortion within the inorganic framework, altering bond lengths and angles and ultimately resulting in decreased elastic constants. An analysis of the absorption coefficient revealed lower attenuation coefficients as the FA content increased, indicating reduced damping effects and internal friction. The current findings can facilitate the fundamental understanding of mixed lead chloride perovskite materials and pave the way for future investigations to exploit the unique properties of mixed halide perovskites for advanced optoelectronic applications.

Fabrication of CH3NH3SnCl3 perovskite nanocrystal-based electrode for supercapacitor devices application

Lead-free halide perovskites nanocrystals (NCs) have been widely used not only in the field of optoelectronics but also in energy storage applications like electrochemical supercapacitors, which could replace electrochemical batteries due to their high power density and long cycle life. The low energy density of supercapacitors is one of the main reasons why they have limited commercial applications. Herein, we have reported synthesis of 3D methylammonium tin chloride perovskite (MASnCl3) nanocrystals (NCs) via a ligand-assisted re-precipitation process (LARP) and determined its performance as an electrochemical supercapacitor. The formation of MASnCl3 NCs is confirmed by different characterization tools. The supercapacitor performances of the synthesized NCs are studied by using three-electrode electrochemical measurements. The maximum specific capacitance, energy density, and power density are found to be 2050 Fg−1, 12 kWKg−1, and 102 WhKg−1, respectively. The charge storage mechanism is estimated from the power law equation by studying the diffusion-limited and capacitive processes and it has been found that the capacitance is 94.16 % capacitive to 5.84 % diffusive in nature. The supercapacitor performance of the synthesized MASnCl3 NCs are studied by fabricating a metal coin-based two-electrode system in which PVA-H2SO4 as solid state electrolyte and NCs act as an active material. The device has retained 80.7 % of its initial specific capacitance value even after 1000 GCD cycles. Interestingly, the developed device showed almost similar gravimetric capacitance value and is enabled to glow a light emitting diode (LED) smoothly.

Alkylammonium lead chloride perovskites: Synthesis, characterization and catalytic activity for conversion of lignin into value added products

Lignin is the utmost abundant source of renewable aromatics hence its depolymerization into functionalized aromatics is attractive but challenging as well. A lot of interest is diverting to photocatalysis as a promising sustainable approach to depolymerizing lignin. In the present studies, photocatalytic lignin depolymerization has been investigated under UV-light irradiation using i-propylamine lead chloride perovskites (AS1-AS3) as catalysts. These catalysts were characterized by Powder X-ray Diffraction, Scanning Electron Microscopy, Ultraviolet–Visible, Photoluminescence, and Fourier Transform Infra-Red Spectroscopic techniques to evaluate crystallite size, surface morphology, band gaps, and quantum yields. Depolymerization of lignin was monitored by taking UV spectra and catalytic pathways were studied through various kinetic models. The depolymerization extent was monitored for different catalyst doses (0.05g–0.1 g), lignin concentration (50ppm–200 ppm), and temperatures (25–100 °C). More than 50% depolymerization rate was obtained for each catalyst using 100 ppm lignin concentration. AS3 has shown maximum efficiency in depolymerizing lignin. Pseudo-first order and modified Freundlich were found to be best-fitted kinetic models for experimental data of lignin depolymerization. The activation energy (Ea) for the depolymerization reaction was calculated to be 6.8 kJ/mol which is extraordinarily less than conventional depolymerization of lignin exhibiting significant catalytic competencies of synthesized catalysts. One of the products (L-AS3) of lignin depolymerization activity carried out at room temperature was characterized through GCMS analysis which indicated the breakdown of the polymeric structure of lignin into small monomeric functionalities. 2-methoxy-4-methylphenol (9%), benzene (4%), cyclohexene (16%), phenol (6%), catechol (12%) and 2-methoxy-5-propenyl phenol (10%) were detected by GCMS analysis of lignin depolymerization product.

Origin of Broad Emission Induced by Rigid Aromatic Ditopic Cations in Low-Dimensional Metal Halide Perovskites.

The development of broadband emitters based on metal halide perovskites (MHPs) requires the elucidation of structure-emission property correlations. Herein, we report a combined experimental and theoretical study on a series of novel low-dimensional lead chloride perovskites, including ditopic aromatic cations. Synthesized lead chloride perovskites and their bromide analogues show both narrow and broad photoluminescence emission properties as a function of their cation and halide nature. Structural analysis shows a correlation between the rigidity of the ditopic cations and the lead halide octahedral distortions. Density functional theory calculations reveal, in turn, the pivotal role of octahedral distortions in the formation of self-trapped excitons, which are responsible for the insurgence of broad emission and large Stokes shifts together with a contribution of halide vacancies. For the considered MHP series, the use of conventional octahedral distortion parameters allows us to nicely describe the trend of emission properties, thus providing a solid guide for further materials design.

Elusive Double Perovskite Iodides: Structural, Optical, and Magnetic Properties.

Halide double perovskites [A2 MI MIII X6 ] are an important class of materials that have garnered substantial interest as non-toxic alternatives to conventional lead iodide perovskites for optoelectronic applications. While numerous studies have examined chloride and bromide double perovskites, reports of iodide double perovskites are rare, and their definitive structural characterization has not been reported. Predictive models have aided us here in the synthesis and characterization of five iodide double perovskites of general formula Cs2 NaLnI6 (Ln=Ce, Nd, Gd, Tb, Dy). The complete crystal structures, structural phase transitions, optical, photoluminescent, and magnetic properties of these compounds are reported.