Li-Ion Cooperative Migration and Oxy-Sulfide Synergistic Effect in Li P Ge S O Solid-State-Electrolyte Enables Extraordinary Conductivity and High Stability.

Critical to the development of all-solid-state lithium-ion batteries technology are novel solid-state electrolytes with high ionic conductivity and robust stability under inorganic solid-electrolyte operating conditions. Herein, by using density functional theory and molecular dynamics, a mixed oxygen-sulfur-based Li-superionic conductor is screened out from the local chemical structure of β-Li PS to discover novel Li P Ge S O (LPGSO) with high ionic conductivity and high stability under thermal, moist, and electrochemical conditions, which causes oxygenation at specific sites to improve the stability and selective sulfuration to provide an O-S mixed path by Li-S/O structure units with coordination number between 3 and 4 for fast Li-cooperative conduction. Furthermore, LPGSO exhibits a quasi-isotropic 3D Li-ion cooperative diffusion with a lesser migration barrier (≈0.

Achieving Both High Ionic Conductivity and High Interfacial Stability with the LiCBO Solid-State Electrolyte: Design from Theoretical Calculations.

A crystalline solid electrolyte interphase LiCO material with a large band gap shows promise toward next-generation all-solid-state lithium batteries (ASSLBs). However, the inferior ionic diffusivity restricts such structures to a real battery setup. Herein, based on density functional theory calculation and Python materials genomics, we theoretically develop the chemistry and local structural motifs to build a mixed boron-carbon framework LiCBO (LCBO).

Ultrafast Hot Carrier Injection in Au/GaN: The Role of Band Bending and the Interface Band Structure.

Plasmon photochemistry can potentially play a significant role in photocatalysis. To realize this potential, it is critical to enhance the plasmon excited hot carrier transfer and collection. However, the lack of atomistic understanding of the carrier transfer across the interface, especially when the carrier is still "hot", makes it challenging to design a more efficient system.

Electrochemical CO Reduction Builds Solvent Water into Oxygenate Products.

Numerous studies have examined the electrochemical reduction of CO (COR) to oxygenates (e.g., ethanol).

Effects of the c-Si/a-SiO interfacial atomic structure on its band alignment: an ab initio study.

The crystalline-Si/amorphous-SiO (c-Si/a-SiO) interface is an important system used in many applications, ranging from transistors to solar cells. The transition region of the c-Si/a-SiO interface plays a critical role in determining the band alignment between the two regions. However, the question of how this interface band offset is affected by the transition region thickness and its local atomic arrangement is yet to be fully investigated.

Stability of Residual Oxides in Oxide-Derived Copper Catalysts for Electrochemical CO Reduction Investigated with O Labeling.

Oxide-derived (OD) Cu catalysts have high selectivity towards the formation of multi-carbon products (C /C ) for aqueous electrochemical CO reduction (CO R). It has been proposed that a large fraction of the initial oxide can be surprisingly resistant to reduction, and these residual oxides play a crucial catalytic role. The stability of residual oxides was investigated by synthesizing O-enriched OD Cu catalysts and testing them for CO R.

Using Wannier functions to improve solid band gap predictions in density functional theory.

Enforcing a straight-line condition of the total energy upon removal/addition of fractional electrons on eigen states has been successfully applied to atoms and molecules for calculating ionization potentials and electron affinities, but fails for solids due to the extended nature of the eigen orbitals. Here we have extended the straight-line condition to the removal/addition of fractional electrons on Wannier functions constructed within the occupied/unoccupied subspaces. It removes the self-interaction energies of those Wannier functions, and yields accurate band gaps for solids compared to experiments.

Interplay between plasmon and single-particle excitations in a metal nanocluster.

Plasmon-generated hot carriers are used in photovoltaic or photochemical applications. However, the interplays between the plasmon and single-particle excitations in nanosystems have not been theoretically addressed using ab initio methods. Here we show such interplays in a Ag55 nanocluster using real-time time-dependent density functional theory simulations.

Photocatalytic Stability of Single- and Few-Layer MoS₂.

MoS2 crystals exhibit excellent catalytic properties and great potential for photocatalytic production of solar fuels such as hydrogen gas. In this regard, the photocatalytic stability of exfoliated single- and few-layer MoS2 immersed in water is investigated by μ-Raman spectroscopy. We find that while the basal plane of MoS2 can be treated as stable under photocatalytic conditions, the edge sites and presumably also defect sites are highly affected by a photoinduced corrosion process.

DFT+U studies of Cu doping and p-type compensation in crystalline and amorphous ZnS.

Zinc sulfide is an excellent candidate for the development of a p-type transparent conducting material that has great demands in solar energy and optoelectronic applications. Doping with Cu is one potential way to make ZnS p-type while preserving its optical transparency for the solar spectrum; however, this is limited by the extremely low solubility of Cu in ZnS and charge compensation mechanisms that eliminate the p-type characteristics. These mechanisms are different in crystalline (c-ZnS) and amorphous structures (a-ZnS), leading to different tendencies of doping Cu in these two ZnS phases, as well as the feasibility to form the p-type material.

Electronic structures and current conductivities of B, C, N and F defects in amorphous titanium dioxide.

Although titanium dioxide (TiO2) has been extensively studied and widely used in energy and environmental areas, the amorphous form and its related defect properties are poorly understood. Recent studies, however, have emphasized the crucial role of amorphousness in producing competitively good performances in photochemical applications. In this work we have investigated for the first time the effects of various dopants (B, C, N and F) on charge carrier transport in amorphous titanium dioxide (a-TiO2), given that doping is a common technique used to tune the electronic properties of semiconductors, and that the existence of these impurities could also be unintentionally introduced during the synthesis process.

Nanoscale charge localization induced by random orientations of organic molecules in hybrid perovskite CH3NH3PbI3.

Perovskite-based solar cells have achieved high solar-energy conversion efficiencies and attracted wide attentions nowadays. Despite the rapid progress in solar-cell devices, many fundamental issues of the hybrid perovskites have not been fully understood. Experimentally, it is well-known that in CH3NH3PbI3 the organic molecules CH3NH3 are randomly orientated at the room temperature, but the impact of the random molecular orientation has not been investigated.

Oxygen vacancy and hole conduction in amorphous TiO2.

The amorphous titanium dioxide (a-TiO2) has drawn attention recently due to the finding that it holds promise for coating conventional photoelectrodes for corrosion protection while still allowing the holes to transport to the surface. The mechanism of hole conductivity at a level much higher than the edge of the valence band is still a mystery. In this work, an amorphous TiO2 model is obtained from molecular dynamics employing the "melt-and-quench" technique.