A5040182388- Perovskite Materials and Applications
- Advanced Photocatalysis Techniques
- Electronic and Structural Properties of Oxides
- Spectroscopy and Quantum Chemical Studies
- Quantum Dots Synthesis And Properties
- Gas Sensing Nanomaterials and Sensors
- Solid-state spectroscopy and crystallography
- Chalcogenide Semiconductor Thin Films
- Advanced Chemical Physics Studies
- Photochemistry and Electron Transfer Studies
- Electrochemical Analysis and Applications
- Quantum, superfluid, helium dynamics
- Semiconductor materials and devices
- Catalytic Processes in Materials Science
- TiO2 Photocatalysis and Solar Cells
- Copper-based nanomaterials and applications
- Metal-Organic Frameworks: Synthesis and Applications
- Magnetic and transport properties of perovskites and related materials
- Advancements in Solid Oxide Fuel Cells
- ZnO doping and properties
- X-ray Diffraction in Crystallography
- Electrocatalysts for Energy Conversion
- Ga2O3 and related materials
- Electrostatics and Colloid Interactions
- Thermal Expansion and Ionic Conductivity
University of Salerno
2022-2024
University of Basilicata
2022-2024
Italian Institute of Technology
2019-2022
Center for Nano Science and Technology
2021-2022
University of Perugia
2020
École Polytechnique Fédérale de Lausanne
2015-2020
Compugen (Israel)
2020
Institute of Molecular Science and Technologies
2019-2020
Charles Humbert 8
2017-2019
University of Warwick
2011-2014
Tin halide perovskites represent the only realistic route toward lead-free perovskite optoelectronics. Despite significant progress, however, device efficiency and stability of solar cells are still limited by self-p-doping Sn(II) oxidation to Sn(IV). By employing state-of-the-art density functional theory simulations, we unveil mechanistic features energetics → Sn(IV) in pristine defective models. Surprisingly, tin is predicted be considerably unfavorable bulk MASnI3 while it energetically...
We developed a computational procedure to screen many different anchoring groups used or usable connect dye the semiconducting surface in dye-sensitized solar cell. The leads clear identification of that bind strongly and facilitate electron injection at same time, providing clear-cut indications for design new dyes. complicated interplay factors determine final results (preferred adsorption mode, anchor's effect on dye's electronic structure, dye-semiconductor coupling) is illustrated...
Isodensity representation of the hole and electron in excitonic state CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> showing spatial separation polaronic charges.
Abstract The peculiar optoelectronic properties of metal‐halide perovskites, partly underlying their success in solar cells and light emitting devices, are likely related to the complex interplay electronic structural features mediated by formation polarons. In this paper current status polaron physics perovskites is reviewed based on a first‐principles computational perspective, which has delivered hitherto noaccessible insights into associated with materials class. role organic (dipolar)...
Abstract Water‐stable metal halide perovskites could foster tremendous progresses in several research fields where their superior optical properties can make differences. In this work we report clear evidence of water stability a lead‐free perovskite, namely DMASnBr 3 , obtained by means diffraction, and X‐ray photoelectron spectroscopy. Such unprecedented water‐stability has been applied to promote photocatalysis aqueous medium, particular devising novel composite material coupling g‐C N 4...
We provide a consistent description of the electronic levels associated with localized and delocalized excess electrons in liquid water by combining hybrid-functional molecular dynamics simulations grand canonical formulation solutes aqueous solution. The electron localizes cavity an average radius 1.8 Å majority coordination five molecules. vertical binding energy, optical s-p transitions, adiabatic redox level are found to agree closely their experimental counterparts. energy...
We determine the band alignment between various semiconductors and liquid water by combining molecular dynamics (MD) simulations of atomistic interface models, electronic-structure calculations at hybrid-functional GW level, a computational standard hydrogen electrode. Our study comprises GaAs, GaP, GaN, CdS, ZnO, SnO2, rutile TiO2, anatase TiO2. For each semiconductor, we generate models with pH corresponding to point zero charge. The are started from two kinds initial configurations, in...
Abstract The rational design of heterojunctions based on metal halide perovskites (MHPs) is an effective route to create novel photocatalysts run relevant solar‐driven reactions. In this work, experimental and computational study the synergic coupling between a lead‐free Cs 3 Bi 2 Br 9 perovskite derivative g‐C N 4 presented. A boost hydrogen photogeneration by more than one order magnitude recorded when going from pure /g‐C system. Effective catalytic activity also achieved in degradation...
Tin-halide perovskites (THPs) have emerged as promising lead-free for photovoltaics and photocatalysis applications but still fall short in terms of stability efficiency with respect to their lead-based counterpart. A detailed understanding the degradation mechanism THPs a water environment is missing. This Letter presents ab initio molecular dynamics (AIMD) simulations unravel atomistic details THP/water interfaces comparing methylammonium tin iodide, MASnI3, MAPbI3. Our results reveal...
Interplay of radiative and non-radiative recombination processes in tin halide perovskites as a result doping, oxidation defects.
While instability in aqueous environment has long impeded employment of metal halide perovskites for heterogeneous photocatalysis, recent reports have shown that some particular tin (THPs) can be water-stable and active photocatalytic hydrogen production. To unravel the mechanistic details underlying activity THPs, we compare reactivity DMASnBr3 (DMA = dimethylammonium) perovskite against prototypical MASnI3 MASnBr3 compounds (MA methylammonium), employing advanced electronic–structure...
The attachment chemistry of the chromophore onto semiconductor surface influences efficiency electron injection in dye-sensitized solar cells (DSSCs). In this work, we study times for dyes that bind to via phosphonic acid anchoring group and effect on time different binding modes (molecular or dissociative, monodentate bidentate) both TiO2 rutile (110) anatase (101) surfaces. We calculate a large set organic surfaces most stable adsorption geometries group, using model based partitioning...
We study hole and electron polarons in BiVO4 at finite temperature through hybrid functional molecular dynamics simulations. Through the thermodynamic integration method, we obtain transition levels corresponding to localized charges 300 K. observe that polaron achieved this way lie significantly closer each other than those 0 find both within band gap, with binding energies of 0.11 0.88 eV, respectively. Our calculations show localization affects alignment solid/liquid interface...
We investigate redox levels in aqueous solution using a combination of ab initio molecular dynamics (MD) simulations and thermodynamic integration methods. The are performed with both the semilocal Perdew-Burke-Ernzerhof functional nonlocal (rVV10) accounting for van der Waals (vdW) interactions. band edges determined through three different schemes, namely, from energy highest occupied lowest unoccupied Kohn-Sham states, total-energy differences, linear extrapolation density states. It is...
Self-consistent GW calculations with efficient vertex corrections are employed to determine the electronic structure of liquid water. Nuclear quantum effects taken into account through ab initio path-integral molecular dynamics simulations. We reveal a sizable band-gap renormalization up 0.7 eV due hydrogen-bond fluctuations. Our lead band gap 8.9 eV, in accord experimental estimate. further resolve ambiguities band-edge positions The valence-band maximum and conduction-band minimum found at...
We study structural, dynamical, and electronic properties of liquid water through ab initio molecular dynamics (MD) simulations based on a hybrid functional which includes nonlocal van der Waals (vdW) interactions. The dimer, the hexamer, two phases ice are studied as benchmark cases. hydrogen-bond energy depends balance between Fock exchange vdW Moreover, energetic competition extended compact structural motifs is found to be well described by theory provided interactions accounted for....
We determine the ionization potential (IP) and electron affinity (EA) of liquid water together with absolute redox level standard hydrogen electrode (SHE) by combining advanced electronic-structure calculations, ab initio molecular dynamics simulations, thermodynamic integration, alignment at water–vacuum interface. The calculated SHE lies 4.56 eV below vacuum level, close to experimental reference 4.44 inferred Trasatti. band edges are determined through a hybrid functional designed...
The photo-active MIL-125 and MIL-125-NH2 metal–organic frameworks (MOFs), despite having a very similar crystalline structure, exhibit different optical behaviors. Luminescence in decays about 1 ns, while for its amino counterpart, the lifetime of charge carriers is at least order magnitude larger. origin this difference key element understanding photocatalytic behavior when associated with active nanoparticles, that completely absent MIL-125. By performing advanced ab initio electronic...
Abstract Quantum mechanical simulations that include the effects of liquid environment are highly relevant for characterization solid-liquid interfaces, which is crucial design a wide range devices. In this work we present rigorous and systematic study band alignment semiconductors in aqueous solutions by contrasting hybrid explicit/implicit models against explicit atomistic based on density-functional theory. We find consistent results obtained provided first solvation shell treated...
We present a theoretical formulation for studying the pH-dependent interfacial coverage of semiconductor-water interfaces through ab initio electronic structure calculations, molecular dynamics simulations, and thermodynamic integration method. This general methodology allows one to calculate acidity individual adsorption sites on surface consequently pH at point zero charge, pHPZC, preferential mode water molecules, either or dissociative, interface. The proposed method is applied study...
Separate localization of charge carriers for pristine and flat surfaces. Bulk-like physics defects the MAI surface while lower formation energies deeper energy levels PbI<sub>2</sub> surface.
A transient state of the excess electron in liquid water preceding development solvation shell, so-called wet electron, has been invoked to explain spectroscopic observations, but its binding energy and atomic structure have remained highly elusive. Here, we carry out hybrid functional molecular dynamics unveil ultrafast mechanism leading hydrated electron. In pre-hydrated regime, is found repeatedly switch between a quasi-free conduction band localized with 0.26 eV, which assign This...
Metal halide perovskites, of general formula ABX3, show a complex interplay the inorganic BX3 sublattice and organic/inorganic A-site cations, which likely determines some their peculiar optoelectronic properties. Comprehension physics underlying this interaction may reveal further means fine-tuning response. Here, we investigate in depth charge–lattice interactions associated with formation polarons different models prototypical CH3NH3PbI3 perovskite through advanced electronic structure...
There is increasing interest in the role of metal halide perovskites for heterogeneous catalysis. Here, we report a Ge-based 2D perovskite material that shows intrinsic water stability realized through organic cation engineering. Incorporating 4-phenylbenzilammonium (PhBz) demonstrate, by means extended experimental and computational results, PhBz2GeBr4 PhBz2GeI4 can achieve relevant air stability. The creation composites embedding graphitic carbon nitride (g-C3N4) allows proof concept...
The novel 2D quasi-hexagonal phase of covalently bonded fullerene molecules (qHP C