Cooperative Growth of Large Single-Crystal Graphene Islands
June 12, 2014 — Researchers showed that it is possible to grow large, single-crystal graphene islands by controlling the nucleation density, which determines the growth mechanism.
Atom Substitution Gives Stable Performance of Solid Electrolytes
May 07, 2014 — The substitution of Ge for As in Li3AsS4 results in an exceptionally stable ionic conductivity versus temperature, and enhances the ionic conductivity by two orders of magnitude. The performance of solid state batteries is dramatically sensitive to temperature due to the energy barrier associated with Li ion motion.
Origin of anomalous atomic vibrations in efficient thermoelectrics revealed
May 06, 2014 — Thermoelectric SnTe and PbTe compounds were investigated with inelastic neutron scattering (INS) and first-principles calculations to understand the basis of their anharmonic lattice dynamics. The phonon anharmonicity of these materials is of both fundamental importance and of practical interest.
A Bi-Functional Electrolyte Design for Long Lasting Batteries
April 24, 2014 — An innovative design of a bi-functional electrolyte defies the theoretical maximum energy capacity of conventional lithium carbon fluoride (Li-CFx) batteries. This novel design has the potential of enabling the creation of long lasting batteries for implantable medical devices, wearable electronics and other applications.
Light-emitting diodes from monolayer WSe2 p-n junctions
April 24, 2014 — Light emitting diodes (LEDs) with improved efficiency have been realized using monolayers of WSe2 carefully cleaved from high-quality bulk single crystals. This new development has the potential for applications in novel optoelectronic devices, such as on-chip lasers.
Decoding the Resistivity of Solid Electrolytes for Batteries
April 02, 2014 — The atomic-scale origin of grain-boundary (GB) resistance in solid electrolytes has been revealed by electron microscopy and spectroscopy. Inorganic solid electrolytes have the potential for enabling intrinsically safe, energy-dense batteries.
New Composite Electrolyte for Advanced Solid State Batteries Shows that Two is Better than One
February 26, 2014 — A new composite electrolyte for batteries with high conduction has been made by combining two solid electrolytes with complementary properties. The composite optimizes the favorable properties of the individual components while minimizing their limitations and opens the door for the development of new solid-state batteries for energy-dense storage of electricity.
Using neutrons to probe and understand battery interfaces
February 14, 2014 — Neutron reflectometry at the Spallation Neutron Source has revealed the composition and growth characteristics of the spontaneous chemical reaction layer formed between a silicon battery anode and an organic electrolyte that ultimately limits the capacity of the battery. We determined that a 3.
Anomalous Photodeposition of Ag on Ferroelectric Surfaces with Below Bandgap Excitation
February 14, 2014 — Photochemical deposition of elemental Ag nanoparticles on a ferroelectric substrate with sub bandgap transmitted white light indicates light confinement and non-linear optical phenomena. This innovation opens the pathway to unprecedented fine control and optimization of the growth of functional nanostructures for potential applications ranging from chemical sensing to high speed data transfer.
Evidence for non-uniform superconductivity in iron-based materials
January 31, 2014 — Multi-scale bulk and local electronic and structural studies on an iron-based superconductor have revealed, for the first time, an origin of non-bulk superconductivity. Understanding the role of chemical doping in causing superconductivity can potentially lead to the design of advanced high-temperature superconductors (HTS).