相关论文: Electronic and optical excitations of K-Sb and Na-…
Thanks to their favorable electronic and optical properties, sodium-potassium-antimonides are an emerging class of crystals used as photocathodes in particle accelerators. The persisting challenges related to the synthesis and…
In the search for novel materials for vacuum electron sources, multi-alkali antimonides and in particular sodium-potassium-antimonides have been recently regarded as especially promising due to their favorable electronic and optical…
A recent study has established the Na$_2$KSb(Cs) photocathode as a highly efficient emitter of spin-polarized electrons. However, the electronic structure of alkali antimonides remains poorly understood. In this work, we report the first…
New spin-dependent photoemission properties of alkali antimonide semiconductor cathodes are predicted based on the detected optical spin orientation effect and DFT band structure calculations. Using these results, the Na$_2$KSb/Cs$_3$Sb…
Alkali-metal antimonides, especially cesium-potassium-antimonide (CsK2Sb), are strong candidates for next-generation photocathodes in linear accelerators due to their low work-function, fast response, high quantum yield, and ability to…
First-principles methods have recently established themselves in the field of photocathode research to provide microscopic, quantum-mechanical characterization of relevant materials for electron sources. While most of the existing studies…
This study presents a comprehensive first-principles investigation of the optoelectronic and thermoelectric properties of aluminum antimonide (AlSb) in its cubic (F-43m) and hexagonal (P63mc) phases. Structural optimization was performed…
The electronic band structure of Na$_{2}$KSb was studied by a combination of low-energy photoemission spectroscopy and density functional theory (DFT) calculations. The optical and photoemission quantum efficiency (QE) spectra, along with…
Alkali antimonide semiconductor photocathodes provide a promising platform for the generation of high brightness electron beams, which are necessary for the development of cutting-edge probes including x-ray free electron lasers and…
Halide perovskites are currently under intense investigation due to their potential applications in optoelectronics and solar cells. Among them several crystallize in low symmetry lattice structures like trigonal, hexagonal, orthorhombic…
A theory of the electronic structure and excitonic absorption spectra of PbS and PbSe nanowires and nanorods in the framework of a four-band effective mass model is presented. Calculations conducted for PbSe show that dielectric contrast…
Mono- and bi-alkali antimonides, X$_2$YSb (X and Y from Group I), are promising for next-generation electron emitters due to their capability of producing high-quality electron beams. However, these materials are not yet well understood, in…
Ac electrical measurements have been reported for alkali halide mixed crystals that were melt grown from NaCl, KCl and KBr starting materials. They showed a nonlinear variation of all the electrical parameters with the bulk composition.…
We report quantum efficiency (QE) enhancements in accelerator technology relevant antimonide photocathodes (K2CsSb) by interfacing them with atomically thin two-dimensional (2D) crystal layers. The enhancement occurs in a reflection mode,…
Modern advances in generating ultrabright electron beams have unlocked unprecedented experimental advances based on synchrotron radiation. Current challenges lie in improving the quality of electron sources with novel photocathode materials…
The optical spectra of CdSe nanocrystals up to 55 A in diameter are analyzed in a wide range of energies from the fine structure of the low-energy excitations to the so-called high-energy transitions. We apply a symmetry-based method in two…
Aluminum nanocrystals offer a promising platform for plasmonic photocatalysis, yet a detailed understanding of their electron dynamics and consequent photocatalytic performance has been challenging thus far due to computational limitations.…
Alkali antimonides are well established as high efficiency, low intrinsic emittance photocathodes for accelerators and photon detectors. However, conventionally grown alkali antimonide films are polycrystalline with surface disorder and…
Optical excitations in hexagonal nanonetwork materials, for example, Boron-Nitride (BN) sheets and nanotubes, are investigated theoretically. The bonding of BN systems is positively polarized at the B site, and is negatively polarized at…
A systematic study of the electronic properties of single layer Sb (antimonene) nanoribbons is presented. By using a 6-orbital tight-binding Hamiltonian, we study the electronic band structure of finite ribbons with zigzag or armchair…