Abstract Phonon scattering limits charge-carrier mobilities and governs emission line broadening in hybrid metal halide perovskites. Establishing how charge carriers interact with phonons these materials is therefore essential for the development of high-efficiency perovskite photovoltaics low-cost lasers. Here we investigate temperature dependence four commonly studied formamidinium methylammonium perovskites, HC(NH 2 ) PbI 3 , PbBr CH NH discover that from longitudinal optical via Fröhlich...

Photovoltaic devices based on metal halide perovskites are rapidly improving in efficiency. Once the Shockley-Queisser limit is reached, charge-carrier extraction will be limited only by radiative bimolecular recombination of electrons with holes. Yet, this fundamental process, and its link material stoichiometry, still poorly understood. Here we show that methylammonium lead triiodide perovskite can fully explained as inverse process absorption. By correctly accounting for contributions to...

We develop a method for calculating the electron-phonon vertex in polar semiconductors and insulators from first principles. The present formalism generalizes Fröhlich to case of anisotropic materials multiple phonon branches, can be used either as postprocessing correction standard calculations, or conjunction with ab initio interpolation based on maximally localized Wannier functions. demonstrate this by investigating interactions anatase TiO(2), show that significantly reduces electron...

When determining machine-learning models for inter-atomic potentials, the potential energy surface is often described as a non-linear function of descriptors representing two- and three-body atomic distribution functions. It not obvious how choice affects efficiency training accuracy final machine-learned model. In this work, we formulate an efficient method to calculate that can separately represent functions, examine effects including only or descriptors, well both, in regression Our study...

Abstract Machine-learned interatomic potentials enable realistic finite temperature calculations of complex materials properties with first-principles accuracy. It is not yet clear, however, how accurately they describe anharmonic properties, which are crucial for predicting the lattice thermal conductivity and phase transitions in solids and, thus, shape their technological applications. Here we employ a recently developed on-the-fly learning technique based on molecular dynamics Bayesian...

Solar cells based on organic–inorganic lead halide perovskites are currently one of the fastest improving photovoltaic technologies. Understanding fundamental electronic and optical properties CH3NH3PbI3 related metal represents a key step in future development perovskite optoelectronic devices. Here we study quasiparticle band structures, gaps, effective masses hypothetical NH4PbI3, PH4PbI3, AsH4PbI3, SbH4PbI3 within GW method, using Wannier interpolation. We find that gaps decrease as size...

Transition metal oxides (TMOs) host a wealth of exotic phenomena ranging from charge, orbital, and magnetic order to nontrivial topological phases superconductivity. In translate these unique materials properties into novel device functionalities, TMOs must be doped. However, the nature carriers in doped their conduction mechanism at atomic scale remain unclear. Recent angle-resolved photoelectron spectroscopy (ARPES) investigations provided new insight questions, revealing that prototypical...

A new method enables $a\phantom{\rule{0}{0ex}}b\phantom{\rule{0.333em}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ calculations of large and small polarons on the same footing. The authors develop theory computational methodology required to determine ground-state energy wave functions electron hole in semiconductors insulators, without performing explicit supercell calculations. As initial applications,...

We develop a formalism and computational method to study polarons in insulators semiconductors from first principles. Unlike standard calculations requiring large supercells, we solve secular equation involving phonons electron-phonon matrix elements density-functional perturbation theory, spirit similar the Bethe-Salpeter for excitons. show that our approach describes seamlessly small polarons, illustrate its capability by calculating wave functions, formation energies, spectral...

We present an approach to generate machine-learned force fields (MLFF) with beyond density functional theory (DFT) accuracy. Our combines on-the-fly active learning and $\Delta$-machine in order MLFF for zirconia based on the random phase approximation (RPA). Specifically, trained during DFT molecular dynamics simulations is corrected by another that differences between RPA calculated energies, forces stress tensors. Thanks relatively smooth nature of differences, expensive calculations are...

Adsorption of carbon monoxide (CO) on transition-metal surfaces is a prototypical process in surface sciences and catalysis. Despite its simplicity, it has posed great challenges to theoretical modeling. Pretty much all existing density functionals fail accurately describe energies CO adsorption site preference as well simultaneously. Although the random phase approximation (RPA) cures these functional theory failures, large computational cost makes prohibitive study for any but simplest...

We demonstrate an approach for calculating temperature-dependent quantum and anharmonic effects with beyond density-functional theory accuracy. By combining machine-learned potentials the stochastic self-consistent harmonic approximation, we investigate cubic to tetragonal transition in strontium titanate show that paraelectric phase is stabilized by fluctuations. find a quantitative understanding of behavior requires higher-level treatment electronic correlation via random approximation....

Abstract Understanding collective phenomena in quantum materials from first principles is a promising route toward engineering properties and designing new functionalities. This work examines the paraelectric state, an elusive state of matter characterized by smooth saturation ferroelectric instability at low temperature due to fluctuations associated with anharmonic phonon effects. The temperature‐dependent evolution soft mode KTaO 3 range 0–300 K modeled combining density functional theory...

The accurate prediction of solid-solid structural phase transitions at finite temperature is a challenging task, since the dynamics so slow that direct simulations by first-principles (FP) methods are typically not possible. Here, we study $\alpha$-$\beta$ transition Zr ambient pressure means on-the-fly machine-learned force fields. These automatically generated during FP molecular (MD) without need human intervention, while retaining almost accuracy. Our MD successfully reproduce...

Electron-phonon physics has become an integral part of today's materials science world. In this work, the authors present $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ results for zero-point renormalization band gap various semiconductors and insulators. They use a new implementation VASP code that utilizes sophisticated projector augmented wave method to calculate electron-phonon...

Polymers are a class of materials that highly challenging to deal with using first-principles methods. Here, we present an application machine-learned interatomic potentials predict structural and dynamical properties dry hydrated perfluorinated ionomers. An improved active-learning algorithm small number descriptors allows efficiently construct accurate transferable model for this multielemental amorphous polymer. Molecular dynamics simulations accelerated by the accurately reproduce...

Strong many-body interactions in solids yield a host of fascinating and potentially useful physical properties. Here, from angle-resolved photoemission experiments ab initio calculations, we demonstrate how strong coupling conduction electrons with collective plasmon excitations their own Fermi sea leads to the formation plasmonic polarons doped ferromagnetic semiconductor EuO. We observe these exhibit significant tunability charge carrier doping, leading polaronic liquid that is...

Organic lasers have attracted increasing attention owing to their superior characteristics such as lightweight, low-cost manufacturing, high mechanical flexibility, and emission-wavelength tunability. Recent breakthroughs include electrically pumped organic laser diodes an driven laser, integrated with light-emitting diode pumping. However, the availability of efficient deep blue chromophores remains limited. In this study, we develop two novel rigid oligophenylenes, end-capped carbazole...

We develop a first-principles approach based on many-body perturbation theory to investigate the effects of interaction between electrons and carrier plasmons electronic properties highly-doped semiconductors oxides. Through evaluation electron self-energy, we account simultaneously for electron-plasmon electron-phonon coupling in theoretical calculations angle-resolved photoemission spectra, linewidths, relaxation times. apply this methodology electron-doped anatase TiO2 as an illustrative...

Abstract Many transition metal oxides (TMOs) are Mott insulators due to strong Coulomb repulsion between electrons, and exhibit metal-insulator transitions (MITs) whose mechanisms not always fully understood. Unlike most TMOs, minute doping in CaMnO 3 induces a metallic state without any structural transformations. This material is thus an ideal platform explore band formation through the MIT. Here, we use angle-resolved photoemission spectroscopy visualize how electrons delocalize couple...

The hydration free energy of atoms and molecules adsorbed at liquid–solid interfaces strongly influences the stability reactivity solid surfaces. However, its evaluation is challenging in both experiments theories. In this work, a machine learning aided molecular dynamics method proposed applied to oxygen hydroxyl groups on Pt(111) Pt(100) surfaces water. adopts thermodynamic integration with respect coupling parameter specifying path from well-defined non-interacting species fully...

Kohn–Sham density functional theory (DFT) is the standard method for first-principles calculations in computational chemistry and materials science. More accurate theories such as random-phase approximation (RPA) are limited application due to their large cost. Here, we use machine learning map RPA a pure functional. The learned model (ML-RPA) nonlocal extension of gradient approximation. descriptors used ingredients enhancement factor counterparts local its gradient. Rather than fitting...

The performance of dye-sensitized solar cells is tightly linked to the relative energy level alignment its constituents. In this paper electronic properties a model cell are studied by accurate first-principle calculations taking into account many-body effects beyond density-functional theory. includes one layer co-adsorbed solvent (water or acetonitrile) molecules. Solvent molecules induce an upwards shift in ${\mathrm{TiO}}_{2}$ bands; such larger case acetonitrile. determination levels...

In the present work atomic, electronic and optical properties of two-dimensional graphene, borophene, boron carbide heterojunction bilayer systems (Graphene-BC