A5060737364- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Solid-state spectroscopy and crystallography
- 2D Materials and Applications
- Crystal Structures and Properties
- Advanced Semiconductor Detectors and Materials
- Semiconductor materials and devices
- Physics of Superconductivity and Magnetism
- Electrocatalysts for Energy Conversion
- Ferroelectric and Negative Capacitance Devices
- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Microwave Dielectric Ceramics Synthesis
- Atmospheric aerosols and clouds
- Inorganic Chemistry and Materials
- Atmospheric chemistry and aerosols
- ZnO doping and properties
- Fuel Cells and Related Materials
- Phase-change materials and chalcogenides
- Thermal Expansion and Ionic Conductivity
University of Illinois Chicago
2022-2025
Washington University in St. Louis
2017-2024
Argonne National Laboratory
2022-2023
Two major challenges hinder the advance of aqueous zinc metal batteries for sustainable stationary storage: (1) achieving predominant Zn-ion (de)intercalation at oxide cathode by suppressing adventitious proton co-intercalation and dissolution, (2) simultaneously overcoming Zn dendrite growth anode that triggers parasitic electrolyte reactions. Here, we reveal competition between Zn2+ vs intercalation chemistry a typical using ex-situ/operando techniques, alleviate side reactions developing...
Abstract High‐entropy alloys combine multiple principal elements at a near equal fraction to form vast compositional spaces achieve outstanding functionalities that are absent in with one or two elements. Here, the prediction, synthesis, and multiscale characterization of 2D high‐entropy transition metal dichalcogenide (TMDC) four/five metals is reported. Of these, electrochemical performance five‐component alloy highest configurational entropy, (MoWVNbTa)S 2 , investigated for CO conversion...
Wildfires emit large amounts of black carbon and light-absorbing organic carbon, known as brown into the atmosphere. These particles perturb Earth's radiation budget through absorption incoming shortwave radiation. It is generally thought that loses its absorptivity after emission in atmosphere due to sunlight-driven photochemical bleaching. Consequently, atmospheric warming effect exerted by remains highly variable poorly represented climate models compared with relatively nonreactive...
We report the discovery of a novel form Ruddlesden–Popper (RP) nickelate that stands as first example long-range, coherent polymorphism in this class inorganic solids. Rather than well-known, uniform stacking perovskite blocks ubiquitously found RP phases, newly discovered polymorph bilayer phase La3Ni2O7 adopts sequence which single-layer and trilayer NiO6 octahedra alternate "1313" sequence. Crystals new are described space group Cmmm, although we note evidence for competing Imam variant....
Abstract To evaluate the role of planar defects in lead‐halide perovskites—cheap, versatile semiconducting materials—it is critical to examine their structure, including defects, at atomic scale and develop a detailed understanding impact on electronic properties. In this study, postsynthesis nanocrystal fusion, aberration‐corrected scanning transmission electron microscopy, first‐principles calculations are combined study nature different formed CsPbBr 3 nanocrystals. Two types prevalent...
The square-planar nickelates are a class of superconductors analogous to the cuprates and promise provide insight into pairing mechanism in high-temperature superconducting oxides. parent phase doped films is ${\mathrm{NdNiO}}_{2}$, which prepared by reducing ${3}^{+}$ Ni ${\mathrm{NdNiO}}_{3}$ films. In this paper, we develop an ultrahigh vacuum reduction method using aluminum deposited on top monitor process real time through situ crystal truncation rod measurements diffraction x-ray...
Methylammonium lead iodide (CH3NH3PbI3 or MAPbI3) perovskite is a promising new photovoltaic material with high power conversion efficiency. However, its phase corner-connected PbI6 octahedra shows poor environmental stability. More recently, MAPbI3 has been shown to be thermodynamically unstable positive formation enthalpy. Here, using first-principles density functional theory calculations, we predict layered hexagonal of consisting infinite chains face-shared P63mc space-group symmetry...
Crystalline solids exhibiting glass-like thermal conductivity have attracted substantial attention both for fundamental interest and applications such as thermoelectrics. In most crystals, the competition of phonon scattering by anharmonic interactions crystalline imperfections leads to a non-monotonic trend with temperature. Defect-free crystals that exhibit glassy low monotonic increase temperature are desirable because they intrinsically thermally insulating while retaining useful...
Chalcogenide perovskites have emerged as a new class of optoelectronic materials, especially for photovoltaic applications, but fundamental properties and applications chalcogenide remain limited due to the lack high-quality thin films. We report direct epitaxial film growth BaZrS3, prototypical chalcogenide, by pulsed laser deposition. X-ray diffraction studies show that films are strongly textured out-of-plane clear in-plane relationship with substrate. Electron microscopy confirm presence...
Materials with large birefringence (Δn, where n is the refractive index) are sought after for polarization control (e.g., in wave plates, polarizing beam splitters, etc.), nonlinear optics, micromanipulation, and as a platform unconventional light-matter coupling, such hyperbolic phonon polaritons. Layered 2D materials can feature some of largest optical anisotropy; however, their use most systems limited because axis out plane layers weakly attached. This work demonstrates that bulk crystal...
It is shown that structural disorder-in the form of anisotropic, picoscale atomic displacements-modulates refractive index tensor and results in giant optical anisotropy observed BaTiS
Solar cells made up of lead-halide perovskites have shown a remarkable increase in power conversion efficiency; however, they are plagued with instability issues that, combined the toxicity lead, led to search for new semiconductors heavy and nontoxic metals such as bismuth. Here, we report on new, inorganic, double perovskite oxide semiconductor: KBaTeBiO6, which has an experimental indirect band gap 1.88 eV shows excellent stability. We data analytics high throughput density functional...
Lead–halide perovskite nanocrystals (PNCs) have attracted much attention in recent years due to their outstanding optical properties. We report here a new chemical route for triggering postsynthetic growth of CsPbBr3 PNCs at room temperature via intentional depletion stabilizing ligands, resulting an immediate fusion the as-synthesized PNCs. Upon fusion, can grow from ca. 8 nm 60 lateral dimensions 48 h, reaching about 14 thickness. More importantly, it was found that fused significantly...
Identifying point defects and other structural anomalies using scanning transmission electron microscopy (STEM) is important to understand a material's properties caused by the disruption of regular pattern crystal lattice. Due improvements in instrumentation stability optics, atomic-resolution images with field view several hundred nanometers can now be routinely acquired at 1-10 Hz frame rates such data, which often contain thousands atomic columns, need analyzed. To date, image analysis...
High quality methylammonium bismuth iodide films made using atmospheric pressure chemical vapor deposition.
Electrical modulation of magnetic states in single-phase multiferroic materials, using domain-wall magnetoelectric (ME) coupling, can be enhanced substantially by controlling the population density ferroelectric (FE) domain walls during polarization switching. In this work, we investigate ME coupling h-YbFeO3 thin films, which FE induce clamped antiferromagnetic (AFM) with reduced magnetization magnitude. Simulation according to phenomenological theory indicates that effect is dramatically...
Abstract Sodium–oxygen (Na–O 2 ) batteries are considered a promising energy storage alternative to current state‐of‐the‐art technologies owing their high theoretical density, along with the natural abundance and low price of Na metal. The chemistry these depends on sodium superoxide (NaO or peroxide (Na O being formed/decomposed. Most Na–O form NaO , but reversibility is usually quite limited due side reactions at interfaces. By using new materials, including highly active catalyst based...
Skyrmions hold great promise for low-energy consumption and stable high-density information storage, stabilization of the skyrmion lattice (SkX) phase at or above room temperature is greatly desired practical use. The topological Hall effect can be used to identify candidate systems temperature, a challenging regime direct observation by Lorentz electron microscopy. Atomically ordered FeGe thin films are grown epitaxially on Ge(111) substrates with $\ensuremath{\sim}4%$ tensile strain....
SUMMARY Low-temperature plastic rheology of calcite plays a significant role in the dynamics Earth's crust. However, it is technically challenging to study at low temperatures because high confining pressures required inhibit fracturing. Micromechanical tests, such as nanoindentation and micropillar compression, can provide insight into under these conditions because, due small scale, deformation be achieved without need for secondary confinement. In this study, compression experiments were...
Lead halide perovskites have emerged as a promising class of semiconductors; however, they suffer from issues related to lead toxicity and instability. We report results first-principles-based design heavy-metal-based oxynitrides alternatives perovskites. used density functional theory calculations search vast composition space ABO2N ABON2 compounds, where B is p-block cation A an alkaline, alkali-earth, rare-earth, or transition metal cation, identify 10 new oxynitride semiconductors that...
To determine the effect of depolarization and critical thickness in improper-ferroelectric hexagonal-ferrite thin films, we investigate polarization switching a ferroelectric/dielectric bilayer capacitor structures at 20 K. Experimentally, show that spontaneous persists throughout studied range (3 to 80 unit cell), even with thick (10-nm) dielectric layer, suggesting no practical limit for applications. By fitting using phenomenological theory, remains finite when ferroelectric layer...
A machine-learning approach that we term the ``stochastic replica voting machine'' (SRVM) algorithm is presented and applied to a binary three-class classification problem in materials science. Here, employ SRVM predict candidate compounds capable of forming stable perovskites double further classify ($AB$) solids. The results our ternary classifications compared well those obtained by SVM neural network algorithms.
ADVERTISEMENT RETURN TO ISSUEPREVEnergy FocusNEXTNGenE 2022: Electrochemistry for DecarbonizationJordi Cabana*Jordi CabanaDepartment of Chemistry, University Illinois at Chicago, 60607, United States*[email protected]More by Jordi Cabanahttps://orcid.org/0000-0002-2353-5986, Thomas AlaanThomas AlaanDepartment Physics, StatesMore Alaan, George W. CrabtreeGeorge CrabtreeDepartment StatesJoint Center Energy Storage Research, Argonne National Laboratory, Lemont, 60439, Crabtree, Po-Wei...