A5038577855- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- X-ray Diffraction in Crystallography
- Solid-state spectroscopy and crystallography
- Crystallization and Solubility Studies
- Conducting polymers and applications
- 2D Materials and Applications
- Optical properties and cooling technologies in crystalline materials
- Optical and Acousto-Optic Technologies
- Graphene research and applications
- Acoustic Wave Resonator Technologies
- Organic Electronics and Photovoltaics
- Photorefractive and Nonlinear Optics
- Multiferroics and related materials
- Photonic and Optical Devices
- Terahertz technology and applications
- Mechanical and Optical Resonators
- Spectroscopy and Quantum Chemical Studies
- Organic and Molecular Conductors Research
- Fullerene Chemistry and Applications
- Superconducting and THz Device Technology
- Thermal properties of materials
- Crystal Structures and Properties
- Advanced Photocatalysis Techniques
Columbia University
2022-2025
Kyoto University
1984-2023
Kyoto Bunkyo University
2016-2023
Kyoto University Institute for Chemical Research
2016-2023
Instituto de Investigaciones Químicas
2016
Kyoto Pharmaceutical University
1984
This work provides an efficient way to facilitate both electron and hole extraction in the designated interfaces of perovskite solar cells. A record power conversion efficiency 23.6% for mixed Sn–Pb cell devices is realized.
Abstract The toxicity of lead perovskite hampers the commercialization perovskite-based photovoltaics. While tin is a promising alternative, facile oxidation tin(II) to tin(IV) causes high density defects, resulting in lower solar cell efficiencies. Here, we show that tin(0) nanoparticles precursor solution can scavenge impurities, and demonstrate this treatment leads effectively tin(IV)-free films with strong photoluminescence prolonged decay lifetimes. These are generated by selective...
Since the seminal work on MoS 2 , photoexcitation in atomically thin transition metal dichalcogenides (TMDCs) has been assumed to result excitons, with binding energies order of magnitude larger than thermal energy at room temperature. Here, we reexamine this foundational assumption and show that TMDC monolayers can a substantial population free charges. Performing ultrafast terahertz spectroscopy large-area, single-crystal monolayers, find up ~10% excitons spontaneously dissociate into...
Two simple methods to improve tin halide perovskite film structure are introduced, aimed at increasing the power conversion efficiency of lead free solar cells. First, a hot antisolvent treatment (HAT) was found increase coverage and prevent electrical shunting in photovoltaic device. Second, it discovered that annealing under low partial pressure dimethyl sulfoxide vapor increased average crystallite size. The topographical qualities films substantively improved as result combined...
A series of solvent-coordinated tin halide complexes were prepared as impurity-free precursors for perovskites, and their structures determined by single-crystal X-ray diffraction analysis. Using these precursors, the MASnI3 FASnI3, prepared, electronic photophysical properties examined under inert conditions means photoelectron yield spectroscopy well absorption fluorescence spectroscopies. Their valence bands (MASnI3: -5.02 eV; FASnI3: -5.16 eV) are significantly higher than those MAPbI3...
Organic-inorganic hybrid perovskite solar cells are attracting much attention due to their excellent photovoltaic properties. In these multilayered structures, the device performance is determined by complicated carrier dynamics. Here, we studied photocarrier recombination and injection dynamics in CH3NH3PbI3 using time-resolved photoluminescence (PL) photocurrent (PC) measurements. It found that a peculiar slowdown PL decay time constants of layer occurs for higher excitation powers,...
We investigated the near-band-edge optical responses and photocarrier dynamics of encapsulated long-term stable CH3NH3SnI3 (MASnI3) thin films solar-cell devices. The MASnI3 film prepared with SnF2 exhibited a bandgap 1.25 eV, while without had significantly blueshifted absorption edge. On contrary, PL peak energies were not influenced by addition SnF2. These observations indicate that blueshift edge in SnF2-free sample is due to Burstein–Moss shift induced significant unintentional hole...
Low-dimensional lead-free luminescent halides have emerged as highly promising phosphors for white-light emission. Recently, we reported a broadband blue-emitting copper(I) iodide-based material, Cs3Cu2I5, with high photoluminescence quantum yield (PLQY) (∼90%) and zero-dimensional nature, providing significant dimensionality the photoactive site. However, this material is insufficient emitter owing to deficient yellow In paper, report novel phosphor, CsCu2I3, 1D structure This exhibits...
Abstract Ferroelectricity, a spontaneous and reversible electric polarization, is found in certain classes of van der Waals (vdW) materials. The discovery ferroelectricity twisted vdW layers provides new opportunities to engineer spatially dependent optical properties associated with the configuration moiré superlattice domains network domain walls. Here, we employ near-field infrared nano-imaging nano-photocurrent measurements study minimally WSe 2 . ferroelectric are visualized through...
Metal halide perovskites can be easily fabricated with low-temperature solution processes, and they are a promising class of materials for solar cells, light emitters, nonlinear optical devices. The direct-gap semiconductors sharp absorption edges highly efficient luminescence no Stokes shift. In addition, the exhibit superior optoelectronic properties such as photon recycling long free-carrier diffusion. this review, we discuss fundamental bulk crystals operation principles heterodiode...
Mixed lead-tin (Pb-Sn) halide perovskites with optimum band gaps near 1.3 eV are promising candidates for next-generation solar cells. However, the performance of cells fabricated Pb-Sn is restricted by facile oxidation Sn(ii) to Sn(iv), which induces self-doping. Maltol, a naturally occurring flavor enhancer and strong metal binding agent, was found effectively suppress Sn(iv) formation passivate defects in mixed perovskite films. When used combination scavenging, maltol surface treatment...
Recent research has revealed remarkable properties of the two-dimensional (2D) van der Waals layered crystal CrSBr, which is both a semiconductor and an $A$-type antiferromagnet. Here we show role strong magnetoelastic coupling in generation propagation coherent magnons CrSBr. Time- spatially resolved magneto-optical Kerr effect microscopy reveals two time-varying transient strain fields induced by out-of-plane transverse in-plane longitudinal lattice displacements. These launch wavepackets...
Lead halide perovskites are promising semiconductors for high-performance photonic devices. Because the refractive index determines optimal design and performance limit of semiconductor devices, its change upon external modulations most critical properties advanced applications. Here, we report that perovskite CH3NH3PbCl3 shows a distinct decrease with increasing temperature, i.e., large negative thermo-optic coefficient, which is opposite to those conventional inorganic semiconductors. By...
The commercial development of perovskite-based photovoltaics is hindered by the toxicity lead perovskite. Although tin perovskite a promising alternative, power conversion efficiency solar cells has not reached levels comparable to lead-based devices. Several factors, including facile oxidation tin(II) tin(IV) and difficulties in controlling morphology layers, are responsible for lower efficiency. By closely integrating high-purity materials improved fabrication methods with extensive...
Perovskite materials with tunable electronic and structural characteristics can realize various physical properties including electrical/ionic conduction, ferroelectricity, luminescence. Integrating coupling these in a single perovskite material offer new possibilities for fundamental research applications. In particular, ferroelectricity luminescence would enable novel Here, we report that the metal-free ferroelectric MDABCO (N-methyl-N'-diazabicyclo[2.2.2]octonium)-ammonium triiodide...
Solution-processed metal halide perovskites are attracting significant attention as high-performance photovoltaic materials. The electron-phonon interactions in lead currently the focus of interest because these play an important role to observed superior material properties and high device performance. Here, we investigated coupling lead-free $\mathrm{C}{\mathrm{H}}_{3}\mathrm{N}{\mathrm{H}}_{3}\mathrm{Sn}{\mathrm{I}}_{3}$ thin films by analyzing temperature-dependence photoluminescence...
Abstract Two simple methods to improve tin halide perovskite film structure are introduced, aimed at increasing the power conversion efficiency of lead free solar cells. First, a hot antisolvent treatment (HAT) was found increase coverage and prevent electrical shunting in photovoltaic device. Second, it discovered that annealing under low partial pressure dimethyl sulfoxide vapor increased average crystallite size. The topographical qualities films substantively improved as result combined...
Charge carrier dynamics in perovskite CH3NH3PbI3 solar cells were studied by means of microscopic photoluminescence (PL) and photocurrent (PC) imaging spectroscopy. The PL intensity, lifetime, PC intensity varied spatially on the order several tens micrometers. Simultaneous image measurements revealed a positive correlation between negative intensities. These correlations due to competition photocarrier injection from layer into charge transport recombination within layer. Furthermore, we...
The last five years have seen very active research in the field of environmentally friendly lead-free perovskite solar cells. Tin halide perovskites are certainly one most promising alternatives to lead-based perovskites, while performance present tin-based cells is still relatively low. Nevertheless, recent experiments on thin films with improved quality indicated that tin can, principle, provide a high device performance. In this Perspective, we summarize progress understanding fundamental...
The superior electrical conductivity and optical transparency of indium tin oxide (ITO) make it an ideal electrode material for use in optoelectronic devices such as solar cells. When ITO electrodes are fabricated on very thin plastic substrates, however, the internal stress layer causes substrate to deform, severely limiting device's performance. Herein, is shown that bilayers composed amorphous base a crystalline overlayer lead deformation‐free electrodes. It optimized bilayer structure...
Structure-property relations of Ag<sub>2-3x</sub>Bi<italic>x</italic>I<sub>2</sub> have been revealed.
Metal halide perovskites are semiconductors with many fascinating characteristics and their widespread use in optoelectronic devices has been expected. High-quality thin films single crystals can be fabricated by simple chemical solution processes fundamental electrical, optical, thermal properties changed significantly compositional substitution, particular halogen ions. In this perspective, we provide an overview of phonon metal perovskites, which play a decisive role determining device...