A5024895908- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- 2D Materials and Applications
- Solid-state spectroscopy and crystallography
- Nanocluster Synthesis and Applications
- Conducting polymers and applications
- Crystallography and molecular interactions
- Luminescence Properties of Advanced Materials
- Advanced Thermoelectric Materials and Devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced Photocatalysis Techniques
- Inorganic Chemistry and Materials
- Copper-based nanomaterials and applications
- Ga2O3 and related materials
- Optical properties and cooling technologies in crystalline materials
- Radiation Detection and Scintillator Technologies
- Thermal properties of materials
- Crystal Structures and Properties
- Electronic and Structural Properties of Oxides
- Coral and Marine Ecosystems Studies
- ZnO doping and properties
- Advanced Semiconductor Detectors and Materials
Hebrew University of Jerusalem
2014-2025
Northwestern University
2018-2024
Hybrid organic-inorganic halide perovskites are under intense investigations because of their astounding physical properties and promises for optoelectronics. Lead bromide chloride exhibit intrinsic white-light emission believed to arise from self-trapped excitons (STEs). Here, we report a series new structurally diverse hybrid lead that have broad-band at room temperature. They feature Pb/Br structures which vary 1D face-sharing 3D corner- edge-sharing structures. Through single-crystal...
Two-dimensional (2D) halide perovskites have extraordinary optoelectronic properties and structural tunability. Among them, the Dion-Jacobson phases with inorganic layers stacking exactly on top of each other are less explored. Herein, we present new series 2D perovskites, which adopt general formula A'An-1PbnI3n+1 (A' = 4-(aminomethyl)pyridinium (4AMPY), A methylammonium (MA), n 1-4). By modifying position CH2NH3+ group from 4AMPY to 3AMPY (3AMPY 3-(aminomethyl)pyridinium), changes eclipsed...
The unique hybrid nature of 2D Ruddlesden-Popper (R-P) perovskites has bestowed upon them not only tunability their electronic properties but also high-performance devices with improved environmental stability as compared to 3D analogs. However, there is limited information about inherent heat, light, and air how different parameters such the inorganic layer number length organic spacer molecule affect stability. To gain deeper understanding on matter we have expanded family R-P perovskites,...
Two-dimensional (2D) hybrid organic–inorganic halide perovskites are a preeminent class of low-cost semiconductors whose inherent structural tunability and attractive photophysical properties have led to the successful fabrication solar cells with high power conversion efficiencies. Despite observed superior stability 2D lead iodide over their 3D parent structures, an understanding thermochemical profile is missing. Herein, calorimetric studies reveal that Ruddlesden–Popper (RP) series,...
There is strong interest in improving the environmental stability of hybrid perovskite solar cells while maintaining high efficiency. Here, we solve this problem by using epilayers a wide-band-gap 1D lead iodide perovskitoid structure, based on short organic cation, namely, thiazole ammonium (TA) form (TAPbI3). The capping layer serves to passivate three-dimensional (3D) films, which promotes charge transport, improves carrier lifetime, and prevents ion migration 3D (MA,FA)PbI3 film (MA =...
Abstract High ZT of 1.34 at 766 K and a record high average above 1 in the temperature range 300‐864 are attained n‐type PbTe by engineering temperature‐dependent carrier concentration weakening electron–phonon coupling upon Ga doping. The experimental studies first principles band structure calculations show that doping with introduces shallow level impurity contributing extrinsic carriers imparts deeper ionizes higher temperatures. This adjusts closer to optimum thus maximizes power factor...
Halide perovskites exhibit remarkably high-performance as semiconductors compared to conventional materials because of an unusually favorable combination optoelectronic properties. We demonstrate here that solution-grown single-crystals organic–inorganic hybrid perovskite CH3NH3PbI3 (MAPbI3), implemented in a Schottky-type device design, can produce outstanding hard radiation detectors with high spectral response and low dark current for the first time. MAPbI3 detector achieves excellent...
The advent of the two-dimensional (2D) family halide perovskites and their demonstration in 2D/three-dimensional (3D) hierarchical film structures broke new ground toward high device performance good stability. 2D Dion-Jacobson (DJ) phase are especially attractive solar cells because superior charge transport properties. Here, we report on DJ using a 3-(aminomethyl)piperidinium (3AMP) organic spacer for fabrication mixed Pb/Sn-based perovskites, exhibiting narrow bandgap 1.27 eV long carrier...
Two-dimensional (2D) halide perovskites exhibit excellent potential for optoelectronics because of their outstanding physical properties and structural diversity. White-light emission is one property 2D that originates from self-trapped excitons (STE) in the highly distorted structures. The so-called (110)-oriented are generally believed to be good candidates white-light emitting devices. Here, we report perovskites, C4N2H12PbX4 (X = I, Br, Cl), templated by small cyclic diammonium cation,...
We have investigated the defect perovskites A3M2I9 (A = Cs, Rb; M Bi, Sb) as materials for radiation detection. The phase purity of Bridgman-grown single crystals was confirmed via high-resolution synchrotron X-ray diffraction, while density functional theory calculations (DFT) show surprisingly dispersive bands in out-of-plane direction these layered materials, with low effective masses both holes and electrons. Accordingly, each four showed response to 241Am α-particle irradiation hole...
Organic-inorganic hybrid halide perovskites are promising semiconductors with tailorable optical and electronic properties. The choice of A-site cation to support a three-dimensional (3D) perovskite structure AMX3 (where M is metal X halide) limited by the geometric Goldschmidt tolerance factor. However, this constraint can be relaxed in two-dimensional (2D) perovskites, providing us an opportunity understand how various cations modulate structural properties thereby optoelectronic Here, we...
We show an example of hierarchically designing electronic bands PbSe toward excellent thermoelectric performance. find that alloying 15 mol % PbTe into causes a negligible change in the light and heavy valence band energy offsets (Δ EV) around room temperature; however, with rising temperature it makes Δ EV decrease at significantly higher rate than PbSe. In other words, temperature-induced convergence is accelerated by PbTe. On this basis, applying 3 Cd substitution on Pb sites...
Semiconductor heterostructured seeded nanorods exhibit intense polarized emission, and the degree of polarization is determined by their morphology dimensions. Combined optical atomic force microscopy were utilized to directly correlate emission orientation single nanorods. For both CdSe/CdS sphere-in-rod (S@R) rod-in-rod (R@R), was found be along nanorod's main axis. Statistical analysis for hundreds shows higher polarization, p, R@R (p = 0.83), in comparison S@R 0.75). These results are...
Abstract 2D hybrid halide perovskites with the formula (A′) 2 (A) n ‐1 Pb I 3 +1 have remarkable stability and promising efficiency in photovoltaic optoelectronic devices, yet fundamental understanding of film formation, key to optimizing these is lacking. Here, situ grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) used monitor formation during spin‐coating. This elucidates general mechanism one‐step There are three stages formation: sol–gel, oriented 3D, 2D. Three precursor phases...
The power conversion efficiency (PCE) of halide perovskite solar cells is now comparable to that commercial cells. These are generally based on multication mixed-halide absorbers with nonideal band gaps 1.5-1.6 eV. PCE should be able rise further if the could use narrower-band gap (1.2-1.4 eV). Reducing Pb content semiconductors without sacrificing performance also a significant driver in cell research. Here, we demonstrate mixed Pb/Sn-based perovskites containing oversized...
The detection of γ-rays at room temperature with high-energy resolution using semiconductors is one the most challenging applications. presence even smallest amount defects sufficient to kill signal generated from which makes availability detectors a rarity. Lead halide perovskite exhibit unusually high defect tolerance leading outstanding and unique optoelectronic properties are poised strongly impact applications in photoelectric conversion/detection. Here we demonstrate for first time...
PbTe-based thermoelectric materials are some of the most promising for converting heat into electricity, but their n-type versions still lag in performance p-type ones. Here, we introduce midgap states and nanoscale precipitates using Ga-doping GeTe-alloying to considerably improve PbTe. The GeTe alloying significantly enlarges energy band gap PbTe subsequent Ga doping introduces special that lead an increased density (DOS) effective mass enhanced Seebeck coefficients. Moreover, nucleated...
Two-dimensional (2D) hybrid halide perovskites are promising in optoelectronic applications, particularly solar cells and light-emitting devices (LEDs), for their increased stability as compared to 3D perovskites. Here, we report a new series of structures using propylammonium (PA+), which results Ruddlesden-Popper (RP) with the formula (PA)2(MA)n-1PbnI3n+1 (n = 3, 4) homologous "step-like" (SL) where PbI6 octahedra connect corner- face-sharing motif general (PA)2m+4(MA)m-2Pb2m+1I7m+4 (m 2,...
Magic-sized clusters (MSCs) are renowned for their identical size and closed-shell stability that inhibit conventional nanoparticle (NP) growth processes. Though MSCs have been of increasing interest, understanding the reaction pathways toward nucleation stabilization is an outstanding issue. In this work, we demonstrate high concentration synthesis (1000 mM) promotes a well-defined pathway to form high-purity (greater than 99.9 percent). The resistant typical dissolution Based on insights...
Off-centering and core–shell nanoscale CdSe precipitates lead to high thermoelectric performance for p-type, Te-free PbSe systems.