A5002589066- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Conducting polymers and applications
- Electronic and Structural Properties of Oxides
- Advanced Photocatalysis Techniques
- Solid-state spectroscopy and crystallography
- Copper-based nanomaterials and applications
- Organic Electronics and Photovoltaics
- Molecular Junctions and Nanostructures
- Atomic and Molecular Physics
- Crystal Structures and Properties
- Luminescence Properties of Advanced Materials
- Ga2O3 and related materials
- Magnetic and transport properties of perovskites and related materials
- Gas Sensing Nanomaterials and Sensors
- Particle accelerators and beam dynamics
- Semiconductor materials and interfaces
- 2D Materials and Applications
- Advancements in Solid Oxide Fuel Cells
- Nuclear physics research studies
- Engineering and Materials Science Studies
- Advanced X-ray and CT Imaging
- Optical properties and cooling technologies in crystalline materials
- GaN-based semiconductor devices and materials
Hebrew University of Jerusalem
2018-2025
Center for NanoScience
2025
Hebrew College
2025
Helmholtz-Zentrum Berlin für Materialien und Energie
2020-2024
University of Cambridge
2024
Weizmann Institute of Science
1978-2019
Universitat de València
2018
Delft University of Technology
2018
Azrieli College of Engineering Jerusalem
2018
Direct comparison between perovskite-structured hybrid organic-inorganic methylammonium lead bromide (MAPbBr3) and all-inorganic cesium (CsPbBr3), allows identifying possible fundamental differences in their structural, thermal electronic characteristics. Both materials possess a similar direct optical band gap, but CsPbBr3 demonstrates higher stability than MAPbBr3. In order to compare device properties, we fabricated solar cells, with similarly synthesized MAPbBr3 or CsPbBr3, over...
Improved stability and efficiency of two-terminal monolithic perovskite-silicon tandem solar cells will require reductions in recombination losses. By combining a triple-halide perovskite (1.68 electron volt bandgap) with piperazinium iodide interfacial modification, we improved the band alignment, reduced nonradiative losses, enhanced charge extraction at electron-selective contact. Solar showed open-circuit voltages up to 1.28 volts p-i-n single junctions 2.00 cells. The achieve certified...
Identification of electronic processes at buried interfaces charge-selective contacts is crucial for photovoltaic and photocatalysis research. Here, transient surface photovoltage (SPV) used to study the passivation different hole-selective carbazole-based SAMs. It shown that SPV photoluminescence provide complementary information on charge transfer kinetics trapping/de-trapping mechanisms, trap-assisted non-radiative recombination losses originate from electron trapping SAM-modified...
We investigate the effect of high work function contacts in halide perovskite absorber-based photovoltaic devices. Photoemission spectroscopy measurements reveal that band bending is induced absorber by deposition molybdenum trioxide (MoO3). find direct contact between MoO3 and leads to a chemical reaction, which diminishes device functionality. Introducing an ultrathin spiro-MeOTAD buffer layer prevents yet altered evolution energy levels methylammonium lead iodide (MAPbI3) at interface...
Abstract The fullerene C 60 is commonly applied as the electron transport layer in high‐efficiency metal halide perovskite solar cells and has been found to limit their open circuit voltage. Through ultra‐sensitive near‐UV photoelectron spectroscopy constant final state mode (CFSYS), with an unusually high probing depth of 5–10 nm, perovskite/C interface energetics defect formation investigated. It demonstrated how consistently determine energy level alignment by CFSYS avoid...
Hysteresis in the current–voltage characteristics of hybrid organic–inorganic perovskite-based solar cells is one fundamental aspects these that we do not understand well. One possible cause, suggested for hysteresis, polarization perovskite layer under applied voltage and illumination bias, due to ion migration within perovskite. To study this problem systemically, both regular (light incident through electron conducting contact) so-called inverted hole were studied at different...
High band gap, high open-circuit voltage solar cells with methylammonium lead tribromide (MAPbBr3) perovskite absorbers are of interest for spectral splitting and photoelectrochemical applications, because their good performance ease processing. The physical origin in these similar perovskite-based devices remains only partially understood. Using cross-sectional electron-beam-induced current (EBIC) measurements, we find an increase carrier diffusion length MAPbBr3(Cl)-based upon low...
Through the optimization of perovskite precursor composition and interfaces to selective contacts, we achieved a p-i-n-type solar cell (PSC) with 22.3% power conversion efficiency (PCE). This is new performance record for PSC an absorber bandgap 1.63 eV. We demonstrate that high device originates from synergy between (1) improved quality when introducing formamidinium chloride (FACl) as additive in "triple cation" Cs0.05FA0.79MA0.16PbBr0.51I2.49 (Cs-MAFA) ink, (2) increased open-circuit...
Abstract A new method for enhancing the charge separation and photo‐electrochemical stability of CuBi 2 O 4 photoelectrodes by sequentially depositing Bi 3 CuO layers on fluorine‐doped tin oxide substrates with pulsed laser deposition (PLD), followed rapid thermal processing (RTP), resulting in phase‐pure, highly crystalline films after 10 min at 650 °C, is reported. Conventional furnace annealing similar 72 h 500 °C do not result phase‐pure . The combined PLD RTP approach allow excellent...
I-V-VI2 ternary chalcogenides are gaining attention as earth-abundant, nontoxic, and air-stable absorbers for photovoltaic applications. However, the semiconductors explored thus far have slowly-rising absorption onsets, their charge-carrier transport is not well understood yet. Herein, we investigate cation-disordered NaBiS2 nanocrystals, which a steep onset, with coefficients reaching >105 cm-1 just above its pseudo-direct bandgap of 1.4 eV. Surprisingly, also observe an ultrafast...
Abstract Outstanding optoelectronic properties of mixed tin‐lead perovskites are the cornerstone for development high‐efficiency all‐perovskite tandems. However, recombination losses in Sn‐Pb still limit performance these perovskites, necessitating more fundamental research. Here, rubidium iodide is employed as an additive methylammonium‐free perovskites. It first investigated effect RbI on perovskite composition, crystal structure, and element distribution. Quasi‐Fermi level splitting...
Abstract The performance of five hole‐transporting layers (HTLs) is investigated in both single‐junction perovskite and Cu(In, Ga)Se 2 (CIGSe)‐perovskite tandem solar cells: nickel oxide (NiO x ,), copper‐doped :Cu), NiO +SAM, :Cu+SAM, SAM, where SAM the [2‐(3,‐6Dimethoxy‐9H‐carbazol‐9yl)ethyl]phosphonic acid (MeO‐2PACz) self‐assembled monolayer. devices correlated to charge‐carrier dynamics at HTL/perovskite interface limiting factors these HTLs are analyzed by performing time‐resolved...
Three different measurements on the structure of ${\mathrm{H}}_{3}^{+}$ molecular ion are reported. The all make use a new technique---the foil-induced dissociation fast molecular-ion beam. It is shown that equilaterally triangular in shape. most probable length side triangle determined by three to be 0.97 \ifmmode\pm\else\textpm\fi{} 0.03 \AA{}, 0.95 0.06 and 1.2 0.2 respectively.
Halide perovskite-based solar cells still have limited reproducibility, stability, and incomplete understanding of how they work. We track electronic processes in [CH3NH3]PbI3(Cl) ("perovskite") films vacuo, N2, air, O2, using impedance spectroscopy (IS), contact potential difference, surface photovoltage measurements, providing direct evidence for perovskite sensitivity to the ambient environment. Two major characteristics IS response change with environment, viz. -1- appearance negative...
Obtaining insight into, and ultimately control over, electronic doping of halide perovskites may improve tuning their remarkable optoelectronic properties, reflected in what appear to be low defect densities as expressed various charge transport optical parameters. Doping is important for because it determines the electrical field within semiconducting photoabsorber, which strongly affects collection efficiency photogenerated charges. Here we report on intrinsic methylammonium lead...
High band gap Pb bromide perovskite (APbBr3)-based solar cells, where A is a mixture of formamidinium, methylammonium, and Cs, show significantly higher, relative, VOC losses than their iodide analogs. Using photoluminescence-, quantum efficiency-, surface photovoltage-spectroscopy measurements, we the absence any significant electronically active tail states within bulk (FA0.85MA0.1Cs0.05)PbBr3 absorber. All methods confirm that EG = 2.28 eV for this halide perovskite, HaP. Contact...
We assess a tandem photoelectrochemical cell consisting of W:BiVO4 photoanode top absorber and CuBi2O4 photocathode bottom for overall solar water splitting. show that the oxidizes produces oxygen at potentials ≥0.7 V vs RHE when CoPi is added as cocatalyst. However, does not produce detectable amount hydrogen from reduction even Pt or RuOx cocatalyst because photocurrent primarily goes toward photocorrosion rather than proton reduction. Protecting with CdS/TiO2 heterojunction adding...
Photovoltaic solar cells operate under steady-state conditions that are established during the charge carrier excitation and recombination. However, to date no model of recombination scenario in halide perovskites has been proposed. In this Letter we present such a is based on single type center, which deduced from our measurements illumination intensity dependence photoconductivity ambipolar diffusion length those materials. The relation between results time-resolved measurements, as...
Lead bromide-based halide perovskites are of interest for wide-band-gap (>1.75 eV) absorbers low-cost solar spectrum splitting to boost solar-to-electrical energy conversion efficiency/area by adding them c-Si or Cu(In,Ga)Se2 PV cells and photoelectrochemical fuel synthesis. Deep in-gap electronic states in serve as recombination centers detrimental the cell's photovoltaic performance, especially open-circuit voltage (Voc). We find four different deep defect polycrystalline layers...
Solvated electrons are highly reductive chemical species whose properties remain largely unknown. Diamond materials proposed as a promising emitter of solvated and visible light excitation would enable solar-driven CO2 or N2 reductions reactions in aqueous medium. But sub-bandgap remains challenging. In this work, the role surface states on diamond for charge separation emission both gaseous environments from deep UV to is elucidated. Four different X-ray UV-vis spectroscopy methods applied...
A combined electronic transport-structure characterization of self-assembled monolayers (MLs) alkyl-phosphonate (AP) chains on Al-AlOx substrates indicates a strong molecular structural effect charge transport. On the basis X-ray reflectivity, XPS, and FTIR data, we conclude that "long" APs (C14 C16) form much denser MLs than do "short" (C8, C10, C12). While current through all junctions showed tunneling-like exponential length-attenuation, with sparsely packed AP attenuate relatively more...
Abstract Ternary chalcogenides have emerged as potential candidates for ultrathin photovoltaics, and NaBiS 2 nanocrystals (NCs) gained appeal because of their months‐long phase‐stability in air, high absorption coefficients >10 5 cm −1 , a pseudo‐direct bandgap 1.4 eV. However, previous investigations into NCs used long‐chain organic ligands separating individual during synthesis, which severely limits macroscopic charge‐carrier transport. In this work, these are exchanged short...
Understanding the sub-band gap luminescence in Ruddlesden–Popper 2D metal halide hybrid perovskites (2D HaPs) is essential for efficient charge injection and collection optoelectronic devices. Still, its origins are still under debate with respect to role of self-trapped excitons or radiative recombination via defect states. In this study, we characterized separation, recombination, transport single crystals, exfoliated layers, polycrystalline thin films butylammonium lead iodide (BA2PbI4),...
CdS, BiVO<sub>4</sub>, and Ga<sub>2</sub>O<sub>3</sub> buffer layers were tested between CuBi<sub>2</sub>O<sub>4</sub> TiO<sub>2</sub> in heterojunction photoelectrodes. Photoelectrochemical analysis modulated surface photovoltage spectroscopy revealed that interface hole traps impacted device performance.