A5001582250- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Gold and Silver Nanoparticles Synthesis and Applications
- Perovskite Materials and Applications
- Advanced Photocatalysis Techniques
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Molecular Junctions and Nanostructures
- Advanced biosensing and bioanalysis techniques
- Organic Light-Emitting Diodes Research
- Electrochemical Analysis and Applications
- Organic and Molecular Conductors Research
- Catalytic Processes in Materials Science
- Electrocatalysts for Energy Conversion
- Ga2O3 and related materials
- Electronic and Structural Properties of Oxides
University of Colorado Boulder
2016-2023
National Yang Ming Chiao Tung University
2020
The effects of additives SnF2 (10%) and EDAI2 (1%) on the dynamics carrier relaxation formamidinium tin triiodide (FASnI3) perovskite were studied using femtosecond transient absorption spectra (TAS) with excitation at 600 870 nm. TAS analyzed according to a parallel sequential kinetic model global fit through singular-value decomposition. For nm, two paths found: one involved hot cold carriers in bulk state undergoing shallow bulk-defect-mediated charge recombination; other trap surface...
Type-II and quasi type-II heterostructure nanocrystals are known to exhibit extended excited-state lifetimes compared their single material counterparts because of reduced wave function overlap between the electron hole. However, due fast efficient hole trapping nonuniform morphologies, photophysics dot-in-rod heterostructures more rich complex than this simple picture. Using transient absorption spectroscopy, we observe that behavior electrons in CdS "rod" or "bulb" regions ZnSe/CdS...
The synthesis, characterization, and photophysical properties of 4- 6-coordinate Bi3+ coordination complexes are reported. Bi(bzq)3 (1) [Bi(bzq)2]Br (2) (bzq = benzo[h]quinoline) synthesized by reaction 9-Li-bzq with BiCl3 BiBr3, respectively. Absorption spectroscopy, electrochemistry, DFT studies suggest that 1 has 42% Bi 6s character in its highest-occupied molecular orbital (HOMO) as a result six σ* interactions the bzq ligands. Excitation at 450 nm results broad emission feature 520 nm,...
The first step in light-driven multielectron redox catalysis driven by semiconductor nanocrystals is the transfer of a photoexcited carrier to catalyst. efficiency that defines upper limit on catalysis. Although progress has been made transferring electrons from catalysts for reduction reactions, there little success moving holes water oxidation (WOCs). Here, we describe kinetics hole CdS quantum dot ruthenium polypyridine molecular WOC. Ultrafast transient absorption and photoluminescence...
Surface charge-carrier traps are ubiquitous in colloidal semiconductor nanocrystals and fundamentally impact excited-state relaxation, making it critical to understand both their nature dynamics. Here, using photoluminescence upconversion transient absorption spectroscopy, we study hole trapping the dissociation between electrons trapped holes nonuniform CdSe nanorods monitor subsequent recombination These dynamics described well with a diffusion–annihilation model wherein undergoes random...
We report on the binding of a Ru-based water oxidation catalyst (WOC) to CdS quantum dots (QDs) revealed by 1H NMR spectroscopy. Spin centers within WOC exhibit correlated trends in chemical shift and T2 lifetime shortening upon QD binding. These effects are highly directional function proton position WOC, thus uncovering orientation information relative surface. The data suggest that interacts with surface via Ru terpyridine ligand, an unexpected has important implications for interfacial...
Many ternary and quaternary semiconductors have been made in nanocrystalline forms for a variety of applications, but we little understanding how well their ensemble properties reflect the individual nanocrystals. We examine electronic structure heterogeneities nanocrystals (Ga1–xZnx)(N1–xOx), semiconductor that splits water under visible illumination. use valence electron energy loss spectroscopy (VEELS) scanning transmission microscope to map out spectra (Ga1–xZnx)(N1–xOx) with spatial...