Related papers: Ultrafast Photoluminescence from Graphene
The unique optoelectronic properties of graphene [1] make it an ideal platform for a variety of photonic applications [2], including fast photodetectors [3], transparent electrodes [4], optical modulators [5], and ultra-fast lasers [6].…
Saturable absorption is a non-perturbative nonlinear optical phenomenon that plays a pivotal role in the generation of ultrafast light pulses. Here we show that this effect emerges in graphene at unprecedentedly low light intensities, thus…
Understanding and controlling hot-carrier relaxation in graphene is crucial for advancing ultrafast optoelectronic and terahertz technologies. Here, we investigate carrier cooling dynamics in monolayer and bilayer graphene using…
Using transient absorption (TA) microscopy as a hot electron thermometer we show disorder-assisted acoustic-phonon supercollisions (SCs) best describes the rate-limiting relaxation step in graphene over a wide range of lattice temperatures…
Monolayer graphene absorbs 2.3 percent of the incident visible light. This 'small' absorption has been used to emphasize the visual transparency of graphene, but it in fact means that multilayer graphene absorbs a sizable fraction of…
Direct and inverse Auger scattering are amongst the primary processes that mediate the thermalization of hot carriers in semiconductors. These two processes involve the annihilation or generation of an electron-hole pair by exchanging…
Understanding the phenomenon of intense photoluminescence in carbon materials such as hydrogenated graphene, graphene nanoribbons, etc. is at the forefront of investigations. In this study, six different types of hydrogenated graphene (phG)…
In the last decade, advancements in attosecond spectroscopy have allowed us to study electron motion dynamics in condensed matter. The access to these electron dynamics and, consequently, its control by an ultrafast light field paves the…
Graphene is a novel two-dimensional material with fascinating electrodynamic properties like the ability to support collective electron oscillations (plasmons) accompanied by tight confinement of electromagnetic fields. Our goal is to…
Characteristic properties of secondary electrons emitted from irradiated two-dimensional materials arise from multi-length and time-scale relaxation processes that connect the initial non-equilibrium excited electron distribution with their…
Ultrafast electron dynamics in solids under strong optical fields has recently found particular attention. In dielectrics and semiconductors, various light-field-driven effects have been explored, such as high-harmonic generation,…
The linear electronic dispersion relation of graphene endows the atomically thin carbon layer with a large intrinsic optical nonlinearity, with regard to both parametric and photothermal processes. While plasmons in graphene nanostructures…
Graphene is known to possess strong optical nonlinearity. Its nonlinear response can be further enhanced by graphene plasmons. Here, we report a novel nonlinear electro-absorption effect observed in nanostructured graphene due to excitation…
We report on the development of an ultrafast Transmission Electron Microscope based on a laser-driven cold-field emission source. We first describe the instrument before reporting on numerical simulations of the laser-driven electron…
The infrared (IR) photoresponse of graphene synthesized by an atmospheric chemical vapor deposition (CVD) system using a mixture of hydrogen and methane gases was studied. The IR sensor devices were fabricated using graphene films…
The ultrafast and ultracold electron source, based on laser cooling and trapping of an atomic gas and its subsequent near-threshold photoionization, is capable of generating electron bunches with a high transverse brightness at energies of…
The transient response of an intrinsic graphene, which is caused by the ultrafast interband transitions, is studied theoretically for the range of pumping correspondent to the saturated absorption regime. Spectral and temporal dependencies…
When light is absorbed by a semiconductor, photoexcited charge carriers enhance the absorption of far-infrared radiation due to intraband transitions. We observe the opposite behavior in monolayer graphene, a zero-gap semiconductor with…
We report optical pumping and X-ray absorption spectroscopy experiments at the PAL free electron laser that directly probe the electron dynamics of a graphene monolayer adsorbed on copper in the femtosecond regime. By analyzing the results…
Graphene is a unique two-dimensional (2D) material that has been extensively investigated owing to its extraordinary photonic, electronic, thermal, and mechanical properties. Excited plasmons along its surface and other unique features are…