Publications by Stefano Falletta

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The electron self-interaction is a long-standing problem in density functional theory and is particularly critical in the description of polarons. Polarons are quasiparticles involving charge localization coupled with self-induced lattice distortions. Sinc ...

We develop a unified theoretical framework encompassing one-body and many-body forms of self-interaction. We find an analytic expression for both the one-body and the many-body self-interaction energies, and quantitatively connect the two expressions throu ...

Nonradiative recombination in Cu(In,Ga)Se2 (CIGS) solar cells has long been attributed to the antisite defects MCu (M = In, Ga), but the underlying mechanism is still elusive. Using rigorous first-principles calculations, we demonstrate that the antisites ...

We study the nature of excess electrons in CsPbBr3 and identify several single and double polaronic states. We emphasize the importance of proper inclusion of the self-interaction corrections for the stability of small electron polarons in this material. W ...

Through the use of the piecewise-linearity condition of the total energy, we correct the self-interaction for the study of polarons by constructing nonempirical functionals at the semilocal level of theory. We consider two functionals, the gamma DFT and mu ...

We develop a scheme for finite-size corrections of vertical transition energies and single-particle energy levels involving defect states with built-in ionic polarization in supercell calculations. The method accounts on an equal footing for the screening ...

In this work, we systematically evaluate the accuracy in band gap prediction of range-separated hybrid functionals on a large set of semiconducting and insulating materials and carry out comparisons with the performance of their global counterparts. We obs ...

We use piecewise-linear functionals to study the polaron energy landscape and hopping rates in beta-Ga2O3, which we adopt as an example of an anisotropic material hosting multiple polaronic states. We illustrate various functionals for polaron localization ...

We investigate the synergy occurring in photocatalytic water splitting between the metal-organic framework MIL-125-NH(2)and two co-catalysts, namely NiO and Ni2P, by calculating their band edge alignment with respect to the redox levels of liquid water. Fo ...

We address the many-body self-interaction in relation to polarons in density functional theory. Our study provides (i) a unified theoretical framework encompassing many-body and one-body forms of self-interaction and (ii) an efficient semilocal scheme for ...

Since the preliminary work of Anisimov and co-workers, the Hubbard corrected DFT+U functional has been used for predicting properties of correlated materials by applying on-site effective Coulomb interactions to specific orbitals. However, the determinatio ...

We investigate the migration properties of hole polarons in rutile and anatase TiO2 using Hubbard U semilocal and hybrid functionals with parameters set to enforce the piecewise linearity condition. The polarons in anatase and in rutile are found to be sta ...

Stefano Falletta

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Self-Interaction and Polarons in Density Functional Theory

Polarons free from many-body self-interaction in density functional theory

Chemical Trend of Nonradiative Recombination in Cu(In,Ga)Se2 Alloys

Small Electron Polarons in CsPbBr3: Competition between Electron Localization and Delocalization

Nonempirical semilocal density functionals for correcting the self-interaction of polaronic states

Finite-size corrections of defect energy levels involving ionic polarization

Range-separated hybrid functionals for accurate prediction of band gaps of extended systems

Polaron hopping through piecewise-linear functionals

Unraveling the synergy between metal-organic frameworks and co-catalysts in photocatalytic water splitting

Many-Body Self-Interaction and Polarons

Hubbard U through polaronic defect states

Migration of hole polarons in anatase and rutile TiO2 through piecewise-linear functionals