Grain Boundary Velocity and Curvature are Not Correlated

10/7/2021 | Gregory Rohrer , Robert Suter

To the eye, most common metals and ceramics used in commercial products appear to be uniformly solid. But at the microscopic level, they are polycrystalline, made up of aggregates of grains that have different sizes, shapes, and crystal orientations.

Common Perovskite Superfluoresces at High Temperatures

6/21/2021 | Franky So and Kenan Gundogdu (North Carolina State University)

Results of this study show that the creation and manipulation of collective coherent states in hybrid perovskites can be used as the basic building blocks for quantum applications.

Computationally Driven Genetically Engineered Materials

5/26/2021 | J. Montclare, R. Bonneau, Y. Wadghiri (NYU)

Development of protein biomaterials that are capable of self-assembly into hydrogels has potential in biomedical applications including drug delivery and tissue engineering. A two-stage architecture, called DeepFRI, has been recently developed where functional salinity is established by training its algorithm on annotated structures from PDB and SWISS-MODEL and applying weighted class activation mapping of residues that are critical to function.

A New Pathway to Stable, Low-cost, Flexible Electronics

4/21/2021 | C. Risko, J. Anthony (U. Kentucky) and Jurchescu (Wake Forest)

While progress in material and device design has been astonishing, low environmental and operational stabilities remain longstanding problems obstructing their immediate deployment in real world applications.

Enhancing the Electrocatalytic Activity of Molybdenum Disulfide

3/9/2021 | Sarbajit Banerjee

A) Illustration of the step-wise synthetic process comprising drop-casting, thermal annealing, and hydrothermal sulfidation/selenization used to grow MoS2-xSex/MoO3 nanosheets on carbon fiber paper. (B) SEM image of sample where Se:S=0.48 showing the homogeneous distribution of the nanosheets on carbon filter paper. (C) Raman spectra (514.5 nm excitation) acquired for MoS2-xSex/MoO3 samples with increasing concentration of Se. (D) Low-magnification and HRTEM images of a sample with a Se:S ratio of 0.62 illustrating the layered structure of MoS2/MoSe2. The left inset shows a SAED pattern of the chalcogenide layers.

Quasi 2D Perovskite Laser

2/12/2021 | K. Gundogdu, F. So (NC St. U.)

The So and Gundogdu groups demonstrated a highly efficient, low threshold optically pumped perovskite laser. In quasi 2D perovskites, exciton funneling into low energy 3D domains functions as the gain medium.

Ultrabright Fluorescent Organic Nanoparticles

2/12/2021 | Amar Flood (Indiana U.)

Ultrabright fluorescent nanoparticles (NPs) hold great promise for demanding bioimaging applications. Recently, extremely bright molecular crystals of cationic fluorophores were obtained by hierarchical co-assembly with cyanostar anion-receptor complexes. These small-molecule ionic isolation lattices (SMILES) ensure spatial and electronic isolation to prohibit aggregation quenching of dyes. Here, a simple, one-step supramolecular approach to formulate SMILES materials into NPs is reported.

Emergent Network of Narrow Transport Channels

1/22/2021 | N. Trivedi (OH St. U.), V. Madhavan (UIUC), U. Chatterjee (U. VA), E. Morosan (Rice U.)

(a) Crystal structure of 1T-TiSe2 with Pt substituting for Ti; (b) temperature-dependent transport, STM showing topography (c) and spectroscopy (e), (d) schematic of domain walls, ARPES showing pseudogap formation at the L point.

Combining Experiment and Computation to Control Doping in Thermoelectric Materials

1/15/2021 | Elif Ertekin (UIUC), Eric Toberer (CO Schl. Mines), and Michael Toney (Stanford U.)

The structural evolution along the alloy between the ordered vacancy compound Hg2GeTe4 and Cu2HgGeTe4 was quantified as this alloy space is correlated with major changes in the carrier concentration. The alloy shows strong local ordering despite four distinct cationic species (Cu, Ge, Hg, vacancies) at high concentration. Further, the results indicated that the CuHg defects are driving the carrier concentration in the Cu2xHg2−xGeTe4 alloy

Efficient Electromagnetic Shields in the GHz and Sub-THz Frequency Bands

1/1/2021 | Alexander Balandin (U. California – Riverside)

These novel films are promising for high-frequency communication technologies, which require electromagnetic shielding films that are flexible, lightweight, corrosion resistant, inexpensive, and electrically insulating.

Research Highlights