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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Green synthesis and 3D pharmacophore study of pyrimidine and glucoside derivatives with in vitro potential anticancer and antioxidant activities

A facile and an efficient one-pot green synthesis of pyrimidine derivatives using the environmentally friendly Cerium(IV) ammonium nitrate (CAN) as catalyst and water as a solvent has been described. Some of the synthesized pyrimidines react with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide in ethanol containing potassium hydroxide to give S-glucoside derivatives. The structures of the newly synthesized compounds were elucidated on the basis of their spectral and elemental analyses. In addition, selected derivatives of the products were screened for their anticancer activities against four tumor cell lines using MTT assay and the results showed that some of these compounds have potent cytotoxic effect, as concluded from their IC{sub 50} values. Molecular modeling studies including generation of a 3D pharmacophore model were carried out. The study showed high correlation with the experimental results. Antioxidant activity of the synthesized products was also investigated and most of them showed potent activity.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Novel chromenes and benzochromenes bearing arylazo moiety: molecular docking, in-silico admet, in-vitro antimicrobial and anticancer screening

Novel derivatives of benzochromene 9a–e and chromene 10a–e were synthesized via multi components reaction that utilizes azo dyes, malononitrile, and arylaldehydes as starting materials. The structures of the newly synthesized compounds were elucidated by the IR, {sup 1}H-NMR, {sup 13}C-NMR and mass spectral data. The new synthesized compounds were explored for their in-silico ADMET properties. The docking investigations verified good docking outcomes in terms of score and binding affinities of the examined compounds on the desired proteins, namely the GlcN-6-P synthase and PI3Ks. The in-vitro studies, which encompassed the antibacterial activity against two types of Gm +ve and two of Gm –ve, and the antifungal activity against four fungi micro-organisms were evaluated by the well diffusion method for the synthesized compounds. Moreover, the anticancer activity was tested against three human carcinoma cell lines [human colon carcinoma (HCT-116), human breast adenocarcinoma (MCF-7), and liver carcinoma (HEPG-2)], exhibiting promising anticancer activity in comparison to Vinblastine, Colchicine and Doxorubicin as standard drugs. The data suggests that some of the new derivatives of chromene scaffold which emerged promising in the in-silico molecular docking studies displayed good in-vitro antimicrobial and anticancer activities and could be exploited as leads for further optimization.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Caveolin-1, a binding protein of CD26, is essential for the anti-inflammatory effects of dipeptidyl peptidase-4 inhibitors on human and mouse macrophages

Highlights: • Teneligliptin suppresses inflammation on human and mouse macrophages. • Caveolin-1 is essential for the anti-inflammatory effects of teneligliptin. • Toll-like receptor 4 (TLR4)-induced inflammation is the target of teneligliptin. • The catalytic site of CD26 is involved in TLR4-induced inflammation. We previously reported that inhibition of dipeptidyl peptidase (DPP)-4, the catalytic site of CD26, prevents atherosclerosis in animal models through suppression of inflammation; however, the underlying molecular mechanisms have not been fully elucidated. Caveolin-1 (Cav-1), a major structural protein of caveolae located on the surface of the cellular membrane, has been reported to modulate inflammatory responses by binding to CD26 in T cells. In this study, we investigated the role of Cav-1 in the suppression of inflammation mediated by the DPP-4 inhibitor, teneligliptin, using mouse and human macrophages. Mouse peritoneal macrophages were isolated from Cav-1{sup +/+} and Cav-1{sup −/−} mice after stimulation with 3% thioglycolate. Inflammation was induced by the toll-like receptor (TLR)4 agonist, lipopolysaccharide (LPS), isolated from Escherichia coli. The expression of pro-inflammatory cytokines was determined using reverse transcription-polymerase chain reaction. Co-expression of Cav-1 and CD26 was detected using immunohistochemistry in both mouse and human macrophages. Teneligliptin treatment (10 nmol/L) suppressed the LPS-induced expression of interleukin (IL)-6 (70%) and tumor necrosis factor-α (37%) in peritoneal macrophages isolated from Cav-1{sup +/+} mice. However, teneligliptin did not have any effect on the macrophages from Cav-1{sup −/−} mice. In human monocyte/macrophage U937 cells, teneligliptin treatment suppressed LPS-induced expression of pro-inflammatory cytokines in a dose-dependent manner (1–10 nmol/L). These anti-inflammatory effects of teneligliptin were mimicked by gene knockdown of Cav-1 or CD26 using small interfering RNA transfection. Furthermore, neutralization of these molecules using an antibody against CD26 or Cav-1 also showed similar suppression. Teneligliptin treatment specifically inhibited TLR4 and TLR5 agonist-mediated inflammatory responses, and suppressed LPS-induced phosphorylation of IL-1 receptor-associated kinase 4, a downstream molecule of TLR4. Next, we determined whether teneligliptin could directly inhibit the physical interaction between Cav-1 and CD26 using the Biacore system. Binding of CD26 to Cav-1 protein was detected. Unexpectedly, teneligliptin also bound to Cav-1, but did not interfere with CD26-Cav-1 binding, suggesting that teneligliptin competes with CD26 for binding to Cav-1. In conclusion, we demonstrated that Cav-1 is a target molecule for DPP-4 inhibitors in the suppression of TLR4-mediated inflammation in mouse and human macrophages.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Characterization of fractional cuts of co-solvent enhanced lignocellulosic fractionation lignin isolated by sequential precipitation

We report that lignin valorization is significantly hindered by the intrinsic heterogeneity of its complex structures and variability of biomass feedstocks. Fractionation of lignin can overcome these challenges by producing functionally distinct lignin cuts that can be further tailored to end products. Herein, lignin was extracted and depolymerized from poplar by the co-solvent enhanced lignocellulosic fractionation method with renewable THF to obtain CELF lignin. Several solvents were screened to separate soluble and insoluble fractions from the parent CELF lignin. The ethanol soluble portion was then fractionated into different molecular weight cuts via sequential precipitation of the lignin by reducing the concentration of THF. The physicochemical structures of different CELF lignin cuts were elucidated by GPC and NMR techniques. In conclusio, these results suggest that CELF lignin cuts with lower molecular weight contain progressively higher phenolic and carboxylic acid OH groups, which can be more suitable as green antioxidants than the parent lignin.

09 BIOMASS FUELS↗
DOE OSTI2016

Preparation and improved photocatalytic activity of mesoporous WS{sub 2} using combined hydrothermal-evaporation induced self-assembly method

Highlights: • One-step method for synthesis of mesoporous WS{sub 2} was proposed. • Role of CTAB surfactant on formation of mesoporous WS{sub 2} was elucidated. • Possible growth mechanism of the mesoporous structure is also reported. • 0.1 wt% mesoporous WS{sub 2} catalyst exhibited high photocatalytic activity under UV light. - Abstract: In this paper, we report mesoporous WS{sub 2} nanosheets with a crystalline network that were synthesized using CTAB as a structure-directing agent via self-assembly induced by hydrothermal and thermal evaporation. Powder X-ray diffraction, Raman spectra, and high-resolution X-ray photoelectron spectroscopy results confirmed the formation of WS{sub 2} structures. Scanning electron microscopy and transmission electron microscopy were used to observe the as-prepared mesoporous frameworks. The mesoporous WS{sub 2} nanosheets have a surface area of 197 m{sup 2} g{sup −1}. A possible growth mechanism is reported for these mesoporous WS{sub 2} nanosheets. The mesoporous WS{sub 2} nanosheets demonstrate high photocatalytic activity. Among different concentrations, 0.1 wt% mesoporous WS{sub 2} shows superior catalytic activity compared to pristine WS{sub 2} nanosheets.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Electronic Structure and Performance Bottlenecks of CuFeO 2 Photocathodes

The path to realizing low-cost, stable, and earth-abundant photoelectrodes can be enabled through a detailed understanding of the optoelectronic properties of these materials by combining theory and experimental techniques. Of the limited set of oxide photocathode materials currently available, CuFeO 2 has emerged as a promising candidate warranting detailed attention. Here, highly compact thin films of rhombohedral (3R) CuFeO 2 were prepared via reactive co-sputtering. Despite its 1.43 eV indirect band gap, a cathodic photocurrent of 0.85 mA/cm 2 was obtained at 0.4 V versus reversible hydrogen electrode in the presence of a sacrificial electron acceptor. This unexpected performance was related to inefficient bulk charge separation because of the ultrafast (<1 ps) self-trapping of photogenerated free carriers. The electronic structure of 3R-CuFeO 2 was elucidated through a combination of optical and X-ray spectroscopic techniques and further complemented by first-principles computational methods including a many-body approach for computing the O K-edge X-ray absorption spectrum. Through resonant inelastic X-ray scattering spectroscopy, the visible absorption edges of CuFeO 2 were found to correspond to Cu → Fe metal-to-metal charge transfer, which exhibits a high propensity toward self-trapping. Findings of the present work enable us to understand the performance bottlenecks of CuFeO 2 photocathodes and suggest feasible strategies for improving material limitations.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Resolving Electrode Morphology’s Impact on Platinum Group Metal-Free Cathode Performance Using Nano-CT of 3D Hierarchical Pore and Ionomer Distribution

This paper reports on the characterization of polymer electrolyte fuel cell (PEFC) cathodes featuring a platinum group metal-free (PGM-free) catalyst using nano-scale resolution X-ray computed tomography (nano-CT) and morphological analysis. PGM-free PEFC cathodes have gained significant interest in the past decade since they have the potential to dramatically reduce PEFC costs by eliminating the large platinum (Pt) raw material cost. However, several challenges remain before they are commercially viable. Since these catalysts have lower volumetric activity, the PGM-free cathodes are thicker and are subject to increased gas and proton transport resistances that reduce the performance. To better understand the efficacy of the catalyst and improve electrode performance, a detailed understanding the correlation between electrode fabrication, morphology, and performance is crucial. In this work, the pore/solid structure and the ionomer distribution was resolved in three dimensions (3D) using nano-CT for three PGM-free electrodes of varying Nafion® loading. The associated transport properties were evaluated from pore/particlescale simulations within the nano-CT imaged structure. These characterizations are then used to elucidate the microstructural origins of the dramatic changes in fuel cell performance with varying Nafion® ionomer loading. We show that this is primarily a result of distinct changes in ionomer’s spatial distribution. The significant impact of electrode morphology on performance highlights the importance of PGM-free electrode development in concert with efforts to improve catalyst activity and durability.

42 ENGINEERING↗
DOE OSTI2019

Dynamic Interplay between Copper Tetramers and Iron Oxide Boosting CO2 Conversion to Methanol and Hydrocarbons under Mild Conditions.

Atomically precise subnanometer catalysts are of significant interest because of their remarkable efficiency in a variety of catalytic reactions. However, the dynamic changes of active sites under reaction conditions, in particular, the transition of cluster-oxide interface structure have not yet been well-elucidated, lacking in situ measurements. By using multiple state-of-the-art in situ characterizations, here we show a dynamic interplay between copper tetramers and iron oxides in a single-size Cu-4/Fe2O3 catalyst, yielding an enrichment of surface Cu-4-Fe2+ species under reaction conditions that boosts CO2 hydrogenation at near-atmospheric pressures. During reaction, Cu-4 clusters facilitate the reduction of Fe2O3 producing surface-rich Fe2+ species in the proximate sites. The as-formed Fe2+ species in return promotes CO2 activation and transformation over Cu4 cluster, resulting in strikingly high methanol synthesis at low temperatures and C-1/C-3 hydrocarbon production in a high-temperature regime. The discovery of highly active Cu-4-Fe2+ sites thus provides new insights for the atomic-level design of copper catalyst toward high-efficiency CO2 conversion under mild conditions.

CO2 conversion↗
DOE OSTI2018

Many Body Effects and Icosahedral Order in Superlattice Self-Assembly

Here, we elucidate how nanocrystals “bond” to form ordered structures. For that purpose we consider nanocrystal configurations consisting of regular polygons and polyhedra, which are the motifs that constitute single component and binary nanocrystal superlattices, and simulate them using united atom models. We compute the free energy and quantify many body effects, i.e., those that cannot be accounted for by pair potential (two-body) interactions, further showing that they arise from coalescing vortices of capping ligands. We find that such vortex textures exist for configurations with local coordination number ≤6. For higher coordination numbers, vortices are expelled and nanocrystals arrange in configurations with tetrahedral or icosahedral order. We provide explicit formulas for the optimal separations between nanocrystals, which correspond to the minima of the free energies. Our results quantitatively explain the structure of superlattice nanocrystals as reported in experiments and reveal how packing arguments, extended to include soft components, predict ordered nanocrystal aggregation.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

The pimeloyl-CoA synthetase BioW defines a new fold for adenylate-forming enzymes

Reactions that activate carboxylates through acyl-adenylate intermediates are found throughout biology and include acyl- and aryl-CoA synthetases and tRNA synthetases. Here we describe the characterization of Aquifex aeolicus BioW, which represents a new protein fold within the superfamily of adenylating enzymes. Substrate-bound structures identified the enzyme active site and elucidated the mechanistic strategy for conjugating CoA to the seven-carbon α,ω-dicarboxylate pimelate, a biotin precursor. Proper position of reactive groups for the two half-reactions is achieved solely through movements of active site residues, as confirmed by site-directed mutational analysis. The ability of BioW to hydrolyze adenylates of noncognate substrates is reminiscent of pre-transfer proofreading observed in some tRNA synthetases, and we show that this activity can be abolished by mutation of a single residue. These studies illustrate how BioW can carry out three different biologically prevalent chemical reactions (adenylation, thioesterification, and proofreading) in the context of a new protein fold.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Composition dependence of electronic, magnetic, transport and morphological properties of mixed valence manganite thin films

Mixed-valence manganese oxides present striking properties like the colossal magnetoresistance, metal-insulator transition (MIT) that may result from coexistence of ferromagnetic, metallic and insulating phases. Percolation of such phase coexistence in the vicinity of MIT leads to first-order transition in these manganites. However the length scales over which the electronic and magnetic phases are separated across MIT which appears compelling for bulk systems has been elusive in (La 1-y Pr y ) 1-x CaxMnO 3 films. Here we show the in-plane length scale over which charge and magnetism are correlated in (La 0.4 Pr 0.6 ) 1-x CaxMnO3 films with x = 0.33 and 0.375, across the MIT temperature. We combine electrical transport (resistance) measurements, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and specular/off-specular x-ray resonant magnetic scattering (XRMS) measurements as a function of temperature to elucidate relationships between electronic, magnetic and morphological structure of the thin films. Using off-specular XRMS we obtained the charge-charge and charge-magnetic correlation length of these LPCMO films across the MIT. We observed different charge-magnetic correlation length for two films which increases below the MIT. The different correlation length shown by two films may be responsible for different macroscopic (transport and magnetic) properties.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Impact of sodium vanadium oxide (NaV 3 O 8 , NVO) material synthesis conditions on charge storage mechanism in Zn-ion aqueous batteries

The electrochemical charge storage of sodium vanadate (NaV 3 O 8 or NVO) cathodes in aqueous Zn-ion batteries has been hypothesized to be influenced by the inclusion of structural water for facilitating ion transfer in the material. Materials properties considered important (morphology, crystallite and particle size, surface area) are systematically studied herein through investigation of two NVO materials, NaV 3 O 8 ·0.34H 2 O [NVO(300)] and NaV 3 O 8 ·0.05H 2 O [NVO(500)], with different water content, acicular morphologies with different size and surface area achieved via post-synthesis heat treatment. The electrochemistry of the two materials was evaluated in aqueous Zn-ion cells with 2 M ZnSO 4 electrolyte using cyclic voltammetry, galvanostatic cycling, and rate capability testing. Furthermore, the thinner NVO(300) nanobelts (0.13 μm) demonstrate greater specific capacities and higher effective diffusion coefficients relative to the thicker NVO(500) nanorods. Notably however, while cells containing NVO(500) deliver lower specific capacity, they demonstrate enhanced capacity retention with cycling. The structural changes accompanying oxidation and reduction are elucidated via ex situ X-ray diffraction, transmission electron microscopy, and operando V K-edge X-ray absorption spectroscopy (XAS), where NVO material properties are shown to influence the ion insertion. Operando XAS verified that electron transfer corresponds directly to change in vanadium oxidation state, affirming vanadium redox as the governing electrochemical process.

25 ENERGY STORAGE↗
DOE OSTI2015

Interpreting the nonlinear dielectric response of glass-formers in terms of the coupling model

Nonlinear dielectric measurements at high electric fields of glass-forming glycerol and propylene carbonate initially were carried out to elucidate the dynamic heterogeneous nature of the structural α-relaxation. Recently, the measurements were extended to sufficiently high frequencies to investigate the nonlinear dielectric response of faster processes including the so-called excess wing (EW), appearing as a second power law at high frequencies in the loss spectra of many glass formers without a resolved secondary relaxation. While a strong increase of dielectric constant and loss is found in the nonlinear dielectric response of the α-relaxation, there is a lack of significant change in the EW. A surprise to the experimentalists finding it, this difference in the nonlinear dielectric properties between the EW and the α-relaxation is explained in the framework of the coupling model by identifying the EW investigated with the nearly constant loss (NCL) of caged molecules, originating from the anharmonicity of the intermolecular potential. The NCL is terminated at longer times (lower frequencies) by the onset of the primitive relaxation, which is followed sequentially by relaxation processes involving increasing number of molecules until the terminal Kohlrausch α-relaxation is reached. These intermediate faster relaxations, combined to form the so-called Johari-Goldstein (JG) β-relaxation, are spatially and dynamically heterogeneous, and hence exhibit nonlinear dielectric effects, as found in glycerol and propylene carbonate, where the JG β-relaxation is not resolved and in D-sorbitol where it is resolved. Like the linear susceptibility, χ{sub 1}(f), the frequency dispersion of the third-order dielectric susceptibility, χ{sub 3}(f), was found to depend primarily on the α-relaxation time, and independent of temperature T and pressure P. I show this property of the frequency dispersions of χ{sub 1}(f) and χ{sub 3}(f) is the characteristic of the many-body relaxation dynamics of interacting systems which are governed solely by the intermolecular potential, and thermodynamic condition plays no role in this respect. Although linked to χ{sub 3}(f), dynamic heterogeneity is one of the parallel consequences of the many-body dynamics, and it should not be considered as the principal control parameter for the other dynamic properties of glassforming systems. Results same as χ{sub 3}(f) at elevated pressures had been obtained before by molecular dynamics simulations from the four-points correlation function and the intermediate scattering function. Naturally all properties obtained from the computer experiment, including dynamics heterogeneity, frequency dispersion, the relation between the α- and JG β-relaxation, and the breakdown of the Stokes-Einstein relation, are parallel consequences of the many-body relaxation dynamics governed by the intermolecular potential.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Reversible migration of silver on memorized pathways in Ag-Ge{sub 40}S{sub 60} films

Reversible and reproducible formation and dissolution of silver conductive filaments are studied in Ag-photodoped thin-film Ge{sub 40}S{sub 60} subjected to electric fields. A tip-planar geometry is employed, where a conductive-atomic-force microscopy tip is the tip electrode and a silver patch is the planar electrode. We highlight an inherent “memory” effect in the amorphous chalcogenide solid-state electrolyte, in which particular silver-ion migration pathways are preserved “memorized” during writing and erasing cycles. The “memorized” pathways reflect structural changes in the photodoped chalcogenide film. Structural changes due to silver photodoping, and electrically-induced structural changes arising from silver migration, are elucidated using Raman spectroscopy. Conductive filament formation, dissolution, and electron (reduction) efficiency in a lateral device geometry are related to operation of the nano-ionic Programmable Metallization Cell memory and to newly emerging chalcogenide-based lateral geometry MEMS technologies. The methods in this work can also be used for qualitative multi-parameter sampling of metal/amorphous-chalcogenide combinations, characterizing the growth/dissolution rates, retention and endurance of fractal conductive filaments, with the aim of optimizing devices.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Giant interfacial perpendicular magnetic anisotropy in MgO/CoFe/capping layer structures

Magnetic tunnel junction based on the CoFeB/MgO/CoFeB structures is of great interest due to its application in the spin-transfer-torque magnetic random access memory (STT-MRAM). Large interfacial perpendicular magnetic anisotropy (PMA) is required to achieve high thermal stability. Here, we use the first-principles calculations to investigate the magnetic anisotropy energy (MAE) of the MgO/CoFe/capping layer structures, where the capping materials include 5d metals Hf, Ta, Re, Os, Ir, Pt, and Au and 6p metals Tl, Pb, and Bi. We demonstrate that it is feasible to enhance PMA by using proper capping materials. Relatively large PMA is found in the structures with the capping materials of Hf, Ta, Os, Ir, and Pb. More importantly, the MgO/CoFe/Bi structure gives rise to giant PMA (6.09 mJ/m 2 ), which is about three times larger than that of the MgO/CoFe/Ta structure. The origin of the MAE is elucidated by examining the contributions to MAE from each atomic layer and orbital. Lastly, these findings provide a comprehensive understanding of the PMA and point towards the possibility to achieve the advanced-node STT-MRAM with high thermal stability.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Many-body perturbation theory for understanding optical excitations in organic molecules and solids

Semiconductors composed of organic molecules are promising as components for flexible and inexpensive optoelectronic devices, with many recent studies aimed at understanding their electronic and optical properties. In particular, computational modeling of these complex materials has provided new understanding of the underlying properties which give rise to their excited-state phenomena. Here, this article provides an overview of recent many-body perturbation theory (MBPT) studies of optical excitations within organic molecules and solids. We discuss the accuracy of MBPT within the GW/BSE approach in predicting excitation energies and absorption spectra, and assess the impact of two commonly used approximations, the DFT starting point and the Tamm–Dancoff approximation. Moreover, we summarize studies that elucidate the role of solid-state structure on the nature of excitons in organic crystals. These studies show that a rich physical understanding of organic materials can be obtained from GW/BSE.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

MemGaze: Rapid and Effective Load-Level Memory Trace Analysis

A major challenge of memory analysis tools is combining high-resolution analysis and low overhead measurement. Currently, hardware/software-based analysis of load-level sequences incurs time slowdowns of O(100×). We present MemGaze, a tool for low-overhead, high-resolution memory analysis. MemGaze uses Intel’s Processor Tracing (PT) instruction ptwrite to collect sampled and compressed memory address traces for load-level, sequence-aware analysis of data reuse. We describe multi-resolution analysis for locations vs. operations, accesses vs. spatio-temporal reuse, and reuse (distance, rate, volume) vs. access patterns. Both trace size and resolution are controllable. We use MemGaze to elucidate the memory effects of different data structures and algorithms. For sampled traces that are ˜1% of a full one, analysis metrics have 1-25% MAPE for histograms of varying dynamic sequence lengths. With current suboptimal kernel support (PT runs continuously), MemGaze’s time overhead is typically 10–95%; 7× at worst. However, when PT runs only during samples, overhead is 10–35% on memory intensive regions and correlates with executed ptwrites.

Kilic, Ozgur O.↗
DOE OSTI2017

Light-induced picosecond rotational disordering of the inorganic sublattice in hybrid perovskites

Femtosecond resolution electron scattering techniques are applied to resolve the first atomic-scale steps following absorption of a photon in the prototypical hybrid perovskite methylammonium lead iodide. Following above-gap photoexcitation, we directly resolve the transfer of energy from hot carriers to the lattice by recording changes in the mean square atomic displacements on 10-ps time scales. Measurements of the time-dependent pair distribution function show an unexpected broadening of the iodine-iodine correlation function while preserving the Pb-I distance. This indicates the formation of a rotationally disordered halide octahedral structure developing on picosecond time scales. Here, this work shows the important role of light-induced structural deformations within the inorganic sublattice in elucidating the unique optoelectronic functionality exhibited by hybrid perovskites and provides new understanding of hot carrier-lattice interactions, which fundamentally determine solar cell efficiencies.

36 MATERIALS SCIENCE↗