A5018480547- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Terahertz technology and applications
- Physics of Superconductivity and Magnetism
- Multiferroics and related materials
- Topological Materials and Phenomena
- Laser-Matter Interactions and Applications
- 2D Materials and Applications
- Spectroscopy and Laser Applications
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Advanced Fiber Laser Technologies
- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- Advanced Thermoelectric Materials and Devices
- Spectroscopy Techniques in Biomedical and Chemical Research
- Semiconductor Quantum Structures and Devices
- Photonic and Optical Devices
- Ferroelectric and Piezoelectric Materials
- Solid-state spectroscopy and crystallography
- Magnetic properties of thin films
- Laser Material Processing Techniques
- Advanced Photocatalysis Techniques
- Spectroscopy and Quantum Chemical Studies
- Graphene research and applications
National Yang Ming Chiao Tung University
2016-2025
National Synchrotron Radiation Research Center
2008-2025
Ton Duc Thang University
2025
National Science and Technology Council
2015-2024
University of Washington
2022-2024
Tamkang University
2022
National Cheng Kung University
2022
RIKEN Center for Emergent Matter Science
2019-2020
Southwestern Institute of Physics
2010-2020
Georgi Nadjakov Institute of Solid State Physics
2016
"Spin" has been recently reported as an important degree of electronic freedom to improve the performance electrocatalysts and photocatalysts. This work demonstrates manipulations spin-polarized electrons in CsPbBr3 halide perovskite nanoplates (NPLs) boost photocatalytic CO2 reduction reaction (CO2RR) efficiencies by doping manganese cations (Mn2+) applying external magnetic field. Mn-doped (Mn-CsPbBr3) NPLs exhibit outstanding CO2RR compared pristine due creating after Mn doping. Notably,...
Abstract Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling nuts and bolts hydrogen production. We report use Au@Cu 7 S 4 yolk@shell nanocrystals as dual-plasmonic photocatalysts to achieve remarkable production under visible near illumination. Ultrafast spectroscopic data reveal prevalence long-lived charge separation states both excitation. Combined with advantageous features nanostructures, achieves a peak quantum yield 9.4% at...
Manipulating electronic polarizations such as ferroelectric or spin has recently emerged an effective strategy for enhancing the efficiency of photocatalytic reactions. This study demonstrates control modulated by and magnetic approaches within a two-dimensional (2D) layered crystal copper indium thiophosphate (CuInP2S6) to boost reduction CO2. We investigate substantial influence polarization on CO2 efficiency, utilizing ferroelectric-paraelectric phase transition alignment through...
Abstract Mid-infrared spectroscopy probes molecular vibrations to identify chemical species and functional groups. Therefore, mid-infrared hyperspectral imaging is one of the most powerful promising candidates for using optical methods. Yet high-speed entire bandwidth has not been realized. Here we report a technique that uses chirped pulse upconversion sub-cycle pulses at image plane. This offers lateral resolution 15 µm, field view adjustable between 800 µm × 600 12 mm 9 mm. The produces...
Strong electric-field transients resonant to intersubband transitions in n-type modulation-doped GaAs/AlGaAs quantum wells induce coherent Rabi oscillations, which are demonstrated by a phase-resolved measurement of the light emitted sample. The time evolution polarization is influenced Coulomb-mediated many-body effects. subpicosecond period and phase oscillations controlled properties midinfrared driving pulse.
Ferroelectric photoelectrodes, other than conventional semiconductors, are alternative photo-absorbers in the process of water splitting. However, capture photons and efficient transfer photo-excited carriers remain as two critical issues ferroelectric photoelectrodes. In this work, we overcome aforementioned by decorating BiFeO3 (BFO) surface with Au nanocrystals, thus improving photoelectrochemical (PEC) performance BFO film. We demonstrate that internal field induced spontaneous...
The recent focus on topological insulators is due to the scientific interest in new state of quantum matter as well technology potential for a generation THz optoelectronics, spintronics and computations. It important elucidate dynamics Dirac fermions topologically protected surface state. Hence we utilized novel ultrafast optical pump mid-infrared probe explore near point. femtosecond snapshots relaxation process were revealed by optics. Specifically, fermion-phonon coupling strength cone...
In the present study, structural, morphological, compositional, nanomechanical, and surface wetting properties of Bi2Se3 thin films prepared using a stoichiometric target Se-rich Bi2Se5 are investigated. The were grown on InP(111) substrates by pulsed laser deposition. X-ray diffraction results revealed that all as-grown exhibited highly c-axis-oriented phase with slight shift in angles, presumably due to stoichiometry changes. energy dispersive spectroscopy analyses indicated gives rise...
Quasiparticle dynamics of FeSe single crystals revealed by dual-color transient reflectivity measurements ($\ensuremath{\Delta}R/R$) provides unprecedented information on Fe-based superconductors. The amplitude the fast component in $\ensuremath{\Delta}R/R$ clearly gives a competing scenario between spin fluctuations and superconductivity. Together with transport measurements, relaxation time analysis further exhibits anomalous changes at 90 230 K. former manifests structure phase transition...
Self-assembled vertical nanostructures take advantage of high interface-to-volume ratio and can be used to design new functionalities by the choice a proper combination constituents. However, most studies date have emphasized functional controllability using external electric or magnetic fields. In this study, introduce light (or photons) as an control parameter in self-assembled nanostructure system, we successfully synthesized oxide with CoFe2O4 nanopillars embedded SrRuO3 matrix. The...
Self-assembled nanocomposites have gained much attention over the past decade due to their intriguing properties and functionalities. In this work, we developed a self-assembled nanocomposite photoanode composed of an epitaxial BiVO4 matrix embedded with WO3 mesocrystals for photoelectrochemical (PEC) applications in visible-light regime. The orientation crystal facet interface provides superior template understand intimate contact between two constituent phases. We demonstrate that...
Self‐assembled vertical heterostructure with a high interface‐to‐volume ratio offers tremendous opportunities to realize intriguing properties and advanced modulation of functionalities. Here, composed two visible‐light photocatalysts, BiFeO 3 (BFO) ε ‐Fe 2 O ( ‐FO), is designed investigate its photoelectrochemical performance. The structural characterization the BFO‐FO heterostructures confirms phase separation BFO nanopillars embedded in ‐FO matrix. investigation band structure...
THz radiation is generated from topological insulators using femtosecond laser pulses. Two-channel free carrier absorption with bulk and surface carriers indispensable to explaining the strong dependence of emission power on concentration. The characteristics provide valuable information regarding fundamental properties Dirac fermions. Three-dimensional (TIs) are characterized by a narrow bandgap in cone-like conducting state.1-3 state new quantum matter caused spin–orbit interaction...
Abstract This work reveals the intrinsic carrier transport behavior of 2D organolead halide perovskites based on phase‐pure homologous ( n = 1, 2, and 3) Ruddelsden–Popper perovskite (RPP) (BA) 2 (MA) −1 Pb I 3n+1 single crystals. The field effect transistors with high‐quality exfoliated bulk crystals are fabricated, characteristic output transfer curves measured from individual single‐crystal flakes various values under different temperatures. Unipolar n‐type dominated electrical properties...
Platinum diselenide (PtSe2) is a group-10 two-dimensional (2D) transition metal dichalcogenide that exhibits the most prominent atomic-layer-dependent electronic behavior of "semiconductor-to-semimetal" when going from monolayer to bulk form. This work demonstrates an efficient photoelectrochemical (PEC) conversion for direct solar-to-hydrogen (H2) production based on 2D layered PtSe2/Si heterojunction photocathodes. By systematically controlling number atomic layers wafer-scale PtSe2 films...
Abstract Despite advancements in terahertz (THz) modulators, achieving a balance between large modulation depth (MD) and fast speed scalable devices remains significant challenge. Optically pumped THz modulators with high MD, broad bandwidth, response times are essential for progress technology. Here, MoTe 2 /Si van der Waals (vdW) heterostructures grown via molecular beam epitaxy (MBE) as an optically leveraging its favorable band alignment seamless integration silicon complementary...
Artificially aligned or positioned functional materials are essential building blocks for modern devices and nanoelectronics. Since the emergence of 2D materials, vertical stacking/integration exotic has garnered increasing attention. However, controlling homostructures, e.g. identical conjoined with varying crystalline orientations, magnetism, strain states, along lateral direction remains challenging. Leveraging on freestanding thin film growth techniques, concept twisted homostructures...
Two-dimensional bismuth oxychalcogenide is a rising material system with superior electronic properties. However, lack of high-quality synthesis impedes the exploration fundamental understanding and practical applications. This work presents epitaxial Bi2O2S films on (LaAlO3)0.3(Sr2TaAlO6)0.7 diverse properties by taking advantage lattice compatibility. The atomically resolved sharp interface Bi2O2S/(LaAlO3)0.3(Sr2TaAlO6)0.7 heteroepitaxy observed verification centrosymmetric breaking...
We studied ultrafast dynamics and photoinduced mechanical strain of BiFeO3 thin films by dual-color transient reflectivity measurements (ΔR/R). Anisotropic photostriction in is found to be mainly driven the optical rectification effect. Results at various thicknesses show that estimated sound velocity along [110] direction 4.76 km/s.
Effects of the CPTA-passivated SnO<sub>2</sub> electron transport layer on photocarrier dynamics in perovskite solar cells revealed by ultrafast pump-probe technique.