Real-Space Imaging of Carrier Dynamics of Materials Surfaces by Second-Generation Four-Dimensional Scanning Ultrafast Electron Microscopy.

In the fields of photocatalysis and photovoltaics, ultrafast dynamical processes, including carrier trapping and recombination on material surfaces, are among the key factors that determine the overall energy conversion efficiency. A precise knowledge of these dynamical events on the nanometer (nm) and femtosecond (fs) scales was not accessible until recently. The only way to access such fundamental processes fully is to map the surface dynamics selectively in real space and time.

Quantum confinement-tunable intersystem crossing and the triplet state lifetime of cationic porphyrin-CdTe quantum dot nano-assemblies.

Here, we report a ground-state interaction between the positively charged cationic porphyrin and the negatively charged carboxylate groups of the thiol ligands on the surface of CdTe quantum dots (QDs), leading to the formation of a stable nanoassembly between the two components. Our time-resolved data clearly demonstrate that we can dramatically tune the intersystem crossing (ISC) and the triplet state lifetime of porphyrin by changing the size of the QDs in the nanoassembly.

In situ investigation of thermally influenced phase transformations in (Pb 0.92 Sr 0.08)(Zr 0.65 Ti 0.35)O3 thin films using micro-Raman spectroscopy and X-ray diffraction.

Thin films of ferroelectric strontium-doped lead zirconate titanate [PSZT, (Pb(0.92)Sr(0.08))(Zr(0.