Related papers: Visualizing hot carrier dynamics by nonlinear opti…
Photoinduced carrier dynamics of nanostructures play a crucial role in developing novel functionalities in advanced materials. Optical pump-probe scanning tunneling microscopy (OPP-STM) represents distinctive capabilities of real-space…
Femtosecond point-projection microscopy (fs-PPM) is an electron microscopy technique that possesses a combination of high spatio-temporal resolution and sensitivity to local electric fields. This allows it to visualize ultrafast charge…
Recent advances in the growth of III-V semiconductor nanowires (NWs) hold great promise for nanoscale optoelectronic device applications. Recently, it was found that a small amount of nitrogen (N) incorporation in III-V semiconductor NWs…
Photoexcited metals can produce highly-energetic hot carriers whose controlled generation and extraction is a promising avenue for technological applications. While hot carrier dynamics in Au-group metals have been widely investigated, a…
We present a real-time investigation of ultrafast carrier dynamics in single-wall carbon nanotube bundles using femtosecond time-resolved photoelectron spectroscopy. The experiments allow to study the processes governing the subpicosecond…
Ultrafast pump-probe measurements of plasmonic nanostructures probe the non-equilibrium behavior of excited carriers, which involves several competing effects obscured in typical empirical analyses. Here we present pump-probe measurements…
Understanding the nanoscale carrier dynamics induced by light excitation is the key to unlocking futuristic devices and innovative functionalities in advanced materials. Optical pump-probe scanning tunneling microscopy (OPP-STM) has opened…
Harnessing non-equilibrium hot carriers from plasmonic metal nanostructures constitutes a vibrant research field. It promises to enable control of activity and selectivity of photochemical reactions, especially for solar fuel generation.…
The separation of hot carriers in semiconductors is of interest for applications such as thermovoltaic photodetection and third-generation photovoltaics. Semiconductor nanowires offer several potential advantages for effective hot-carrier…
We demonstrate that ultrafast carrier excitation can drastically affect electronic structures and induce brief surface plasmonic response in non-plasmonic metals, potentially creating a plasmonic switch. Using first-principles molecular…
Direct measurements of photoexcited carrier dynamics in nickel are made using few-femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy at the nickel M$_{2,3}$ edge. It is observed that the core-level absorption lineshape…
Molecular vibrations and their dynamics are of outstanding importance for electronic and thermal transport in nanoscale devices as well as for molecular catalysis. The vibrational dynamics of <100 molecules are studied through three-colour…
Experiments and numerical simulations are described that develop quantitative understanding of atomic motion near the surfaces of nanoscopic photonic crystal waveguides (PCWs). Ultracold atoms are delivered from a moving optical lattice…
The motion of atoms is at the heart of any chemical or structural transformation in molecules and materials. Upon activation of this motion by an external source, several (usually many) vibrational modes can be coherently coupled, thus…
Observing the individual building blocks of matter is one of the primary goals of microscopy. The invention of the scanning tunneling microscope [1] revolutionized experimental surface science in that atomic-scale features on a solid-state…
Semiconductor heterojunctions have gained significant attention for efficient optoelectronic devices owing to their unique interfaces and synergistic effects. Interaction between charge carriers with the heterojunction plays a crucial role…
Few-femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy, performed with optical 500-1000 nm supercontinuum and broadband XUV pulses (30-50 eV), simultaneously probes dynamics of photoexcited carriers in WS$_{2}$ at the W…
Semiconductor devices favor high carrier mobility for reduced Joule heating and high thermal conductivity for rapid heat dissipation. The ability to accurately characterize the motion of charge carriers and heat carriers is necessary to…
Optical pump-terahertz probe spectroscopy has been used to investigate ultrafast photo-induced charge carrier transport in 3.4 $\mu$m wide graphene ribbons upon scaling the optical pump intensity. For low pump fluences, the deposited pump…
We are preparing for an ultra-high resolution x-ray spectroscopy of kaonic atoms using an x-ray spectrometer based on an array of superconducting transition-edge-sensor microcalorimeters developed by NIST. The instrument has excellent…