As all-solid-state batteries (SSBs) develop as an alternative to traditional cells, a thorough theoretical understanding of driving forces behind battery operation is needed. We present fully first-principles-informed model potential profiles in SSBs and apply the Li/LiPON/$\text{Li}_x\text{CoO}_2$ system. The predicts interfacial drops driven by both electron transfer Li$^+$ space-charge layers that vary with SSB's state charge. results suggest lower electronic ionization solid electrolyte...

We report measurements of the diffusion atomic hydrogen in single crystalline VO2 micro/nanobeams by direct exposure to hydrogen, without catalyst. The is generated a hot filament, and doping process takes place at moderate temperature (373 K). Undoped has metal-to-insulator phase transition ∼340 K between high-temperature, rutile, metallic low-temperature, monoclinic, insulating with resistance exhibiting semiconductor-like dependence. Atomic hydrogenation results stabilization down 2 K,...

Semiconductor nanoplatelets (NPLs), with their large exciton binding energy, narrow photoluminescence (PL), and absence of dielectric screening for photons emitted normal to the NPL surface, could be expected become fastest luminophores amongst all colloidal nanostructures. However, super-fast emission is suppressed by a dark (optically passive) ground state, substantially split from higher-lying bright active) state. Here, fine structure in 2-8 monolayer (ML) thick Cs

The lone-pair s states of germanium, tin, and lead underlie many the unconventional properties inorganic metal halide perovskites. Dynamic stereochemical expression lone pairs is well established for perovskites based on all three metals, but previously, only germanium were thought to express pair crystallographically. In this work, we use advanced first-principles calculations with a hybrid functional spin–orbit coupling predict stable monoclinic polar phases CsSnI3 CsSnBr3, which exhibit...

Initiated chemical vapor deposition provides the means to coat thin, conformal polymer films on high surface-area 3D architectures as well planar substrates.

Substitution of vanadium into earth-abundant maghemite iron oxide introduces cation vacancies that increase Li+ storage capacity concomitant with a positive shift in its electrochemical potential. Expressing ferrite (VFe2Ox) as an aerogel offers opportunity to probe this inherently defective spinel from highly disordered (X-ray amorphous) nanocrystalline. To understand the redox sequence host cations, we use situ X-ray absorption near-edge spectroscopy (XANES) obtained using in-lab...

Controlling electronic population through chemical doping is one way to tip the balance between competing phases in materials with strong correlations. Vanadium dioxide exhibits a first-order phase transition at around 338 K high-temperature, tetragonal, metallic state (T) and low-temperature, monoclinic, insulating (M1), driven by electron-electron electron-lattice interactions. Intercalation of VO2 atomic hydrogen has been demonstrated, evidence that this suppresses transition. However,...

We experimentally study the coupling of Group V donor spins in silicon to mechanical strain, and measure strain-induced frequency shifts which are linear contrast quadratic dependence predicted by valley repopulation model (VRM), therefore orders magnitude greater than that VRM for small strains $|\varepsilon| < 10^{-5}$. Through both tight-binding first principles calculations we find these arise from a tuning hyperfine interaction term hydrostatic component strain achieve semi-quantitative...

The performance of solid-state electrochemical systems is intimately tied to the potential and lithium distributions across electrolyte–electrode junctions that give rise interface impedance. Here, we combine two operando methods, Kelvin probe force microscopy (KPFM) neutron depth profiling (NDP), identify rate-limiting in operating Si-LiPON-LiCoO2 batteries by mapping contact difference (CPD) corresponding Li distributions. contributions from ions, electrons, interfaces are deconvolved...

Barium cerate (${\mathrm{BaCeO}}_{3}$) is a well-known ionic conductor of both hydrogen and oxygen. In applications, it frequently doped (for instance with Y) to increase stability promote diffusion. However, the effects doping native defects are not fully understood. Computational studies have been stymied by nature conduction band, which made up cerium $4f$ states. These states present challenge ab initio techniques based on density functional theory within standard approximations for...

We investigate "Posner molecules", calcium phosphate clusters with chemical formula Ca$_9$(PO$_4$)$_6$. Originally identified in hydroxyapatite, Posner molecules have also been observed as free-floating $in$ $vitro$. The formation and aggregation of important implications for bone growth, may play a role other biological processes such the modulation ion concentrations within mitochondrial matrix. In this work, we use first-principles computational methodology to study structure molecules,...

First-principles calculations of CsPbBr₃ find that bromine and hydrogen interstitials exhibit deep defect levels which may lead to non-radiative recombination.

Abstract Spin qubits based on shallow donors in silicon are a promising quantum information technology with enormous potential scalability due to the existence of robust silicon-processing infrastructure. However, most accurate theories donor electronic structure lack predictive power because their reliance empirical fitting parameters, while ab initio methods have so far been lacking accuracy size wavefunction compared typical simulation cells. We show that density functional theory hybrid...

Lead halide perovskites such as methylammonium lead iodide are attractive solar cell materials, and others cesium bromide expected to be high-performing optoelectronic materials with potential applications including lighting, displays, quantum information. All of these will benefit from having fully controlled electrical conductivity, but it has proven difficult achieve high hole concentrations in via impurity doping. In this work, possible acceptor dopants for the (including Ag, Na, Cu)...

While semiconductor nanocrystals provide versatile fluorescent materials for light-emitting devices, their brightness suffers from the "dark exciton"─an optically inactive electronic state into which relax before emitting. Recently, a theoretical mechanism, Rashba effect, was discovered that can overcome this limitation by inverting lowest-lying levels and creating bright excitonic ground state. However, no methodology is available to systematically identify exhibit inversion, hindering...

The Rashba effect has been proposed to give rise a bright exciton ground state in halide perovskite nanocrystals (NCs), resulting very fast radiative recombination at room temperature and extremely low temperature. In this paper we find the dispersion of "Rashba exciton", i.e., whose bulk reflects large spin-orbit terms conduction valence bands thus minima non-zero quasi-momenta. Placing excitonsin quasi-2D cylindrical quantum dots, calculate size-dependent levels confined excitons their...

Abstract The frequency variation of nuclear interactions under lead has been studied by comparing the rates stars in Ilford G5 emulsions exposed above and below 30 cms. lead. size distribution is same for both sets plates. attenuation lengths are :-- (305±7) gm./cm.2 all stars, (380±65) penetrating showers (n s ⩾2), (405±31) gm.]cm.2 events with charged relativistic primaries, (260±34) uncharged primaries (excluding simple evaporatioD stars). ratio length to interaction mean free path...

Studies using molecular dynamics (MD) have long struggled to simulate the failure modes of materials, predicting unrealistically high ductility and failing capture brittle fracture. The primary cause this shortcoming is an inadequate description bond breaking. While reactive force fields such as ReaxFF show improvements compared traditional fields, charge models used yield unphysical partial charges, especially during dissociation ionic bonds. This flaw may be remedied by atom-condensed...

We study the metal-organic framework (MOF) ZIF-67 with 1H and 13C nuclear magnetic resonance (NMR). In addition to usual orbital chemical shifts, we observe spinning sideband manifolds in NMR spectrum due hyperfine interactions of paramagnetic cobalt 13C. Both shifts are good agreement values calculated from first principles, allowing high-confidence assignment observed peaks specific sites within MOF. Our measured line shapes, spin lattice relaxation rates also consistent values. show that...

ScN has attracted great attention for its electronic properties and ability to enhance polarization of AlN; however, sister compounds, YN LaN, remain much less studied. Here, we use first-principles calculations evaluate LaN in their cubic hexagonal phases. Rocksalt are semiconductors, although show that differs from having a direct band gap, which attribute weaker $p\text{\ensuremath{-}}p$ coupling. Both have low electron effective masses. In addition rocksalt structures, the layered...

All-inorganic lead halide perovskites such as cesium bromide (CsPbBr3) are high-performance light emitters with applications in lighting, displays, and quantum information. However, it has proven difficult to achieve high p-type carrier concentrations these materials. In this work, a wide variety of possible acceptor dopants evaluated using first-principles calculations. Connecting the results previous work on native defects, we show that doping is because two related effects: moderately...