Related papers: High-brightness Graphite Photocathodes
The hexagonal structure of graphene gives rise to the property of gas impermeability, motivating its investigation for a new application: protection of semiconductor photocathodes in electron accelerators. These materials are extremely…
We present an experimental observation of non-linear up- and down-converted optical luminescence of graphene and thin graphite subject to picosecond infrared laser pulses. We show that the excitation yields to a high density electron-hole…
We report successful deposition of high quantum efficiency (QE) bialkali antimonide K2CsSb photocathodes on graphene films. The results pave a pathway towards an ultimate goal of encapsulating technologically-relevant photocathodes for…
Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible, and transparent optoelectronics. In particular, the strong light-matter interaction in graphene has allowed for the development of…
Quantum efficiency studies for various wavelength and various technical metal surfaces were carried out in a dedicated unbaked vacuum chamber. Copper, magnesium, aluminium and aluminium-lithium photocathodes were irradiated by two different…
Graphene is a very attractive material for broadband photodetection in hyperspectral imaging and sensing systems. However, its potential use has been hindered by tradeoffs between the responsivity, bandwidth, and operation speed of existing…
Fabrication of graphene structures has triggered vast research efforts focused on the properties of two-dimensional systems with massless Dirac fermions. Nevertheless, further progress in exploring this quantum electrodynamics system in…
The extraordinary properties of graphene make it a very promising material for use in optoelectronics. However, this is still a nascent field, where some basic properties of the electromagnetic field in graphene must be explored. Here we…
Aspects of the preparation process and performance degradation are two major problems of photocathodes. The lack of a means for dynamic quantum efficiency measurements results in the inability to observe the inhomogeneity of the cathode…
Recent investigations of RF copper structures operated at cryogenic temperatures performed by a SLAC-UCLA collaboration have shown a dramatic increase in the maximum surface electric field, to 500 MV/m. We examine use of these fields to…
Amongst the wide spectrum of potential applications of graphene, ranging from transistors and chemical-sensors to nanoelectromechanical devices and composites, the field of photonics and optoelectronics is believed to be one of the most…
A 200 mm processing platform for the large-scale production of graphene field-effect transistor-quantum dot (GFET-QD) hybrid photodetectors is demonstrated. Comprehensive statistical analysis of electric data shows a high yield (96%) and…
Graphene is at the center of a significant research effort. Near-ballistic transport at room temperature and high mobility make it a potential material for nanoelectronics. Its electronic and mechanical properties are also ideal for micro…
Graphene has been recognized as an attractive two-dimensional material for fundamental research and wide applications in electronic and photonic devices owing to its unique properties. The technologies to modulate the properties of graphene…
We report a method to promote photoluminescence emission in graphene materials by enhancing carrier scattering instead of directly modifying band structure in multilayer reduced graphene oxide (rGO) nanospheres. We intentionally curl…
We explore nonlinear photoemission in cesium telluride (Cs$_2$Te) photocathodes where an ultrashort ($\sim 100$ fs full width at half max) 800-nm infrared laser is used as the drive-laser in lieu of the typical $\sim 266$-nm ultraviolet…
The quantum efficiencies (QE) of photocathodes consisting of bulk Nb substrates coated with thin films of Cs2Te are reported. Using the standard recipe for Cs2Te deposition developed for Mo substrates (220 {\AA} Te thickness), a QE ~11% -…
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].…
Graphene, owing to its zero bandgap electronic structure, is promising as an absorption material for ultra-wideband photodetection applications. However, graphene-absorption based detectors inherently suffer from poor responsivity due to…
Ultrafast electrically driven nanoscale light sources are critical components in nanophotonics. Compound semiconductor-based light sources for the nanophotonic platforms have been extensively investigated over the past decades. However,…