No abstract

Borophene monolayer with its intrinsic metallic and anisotropic band structures exhibits extraordinary electronic, optical, and transport properties. Especially, the high density of Dirac electrons enables promising applications for building low-loss broadband SPP devices. However, a systematic characterization of the surface plasmon polariton (SPP) properties and hot carriers generated from the inevitable SPP decay in borophene has not been reported so far. Most importantly, the mechanism for SPP losses remains obscurely quantified. In this work, from a fully first-principles perspective, we explicitly evaluate the main loss effects of SPP in borophene, including the Drude resistance, phonon-assisted intraband and direct interband electronic transitions. With this knowledge, we further calculate the frequency- and polarization-dependent SPP response of borophene, and evaluate some typical application-dependent figure of merits of SPP. On the other hand, we evaluate the generation and transport properties of plasmon-driven hot carriers in borophene, involving energy- and momentum-dependent carrier lifetimes and mean free paths, which provide deeper insight toward the transport of hot carriers at the nanoscale. These results indicate that borophene has promising applications in next-generation low-loss optoelectronic devices and photocatalytic reactors.

No abstract

Metal films down to atomic thickness have superior light absorption ability and conductive properties, especially the surface plasmons excited at the interface of metal film and dielectric can well capture photons and generate hot carriers, making them more efficient in improving the photoelectric conversion efficiency of solar cells, designing photodetectors in the near-infrared band, and sensors based on surface plasmon. However, there is still a lack of systematic theoretical studies on the surface plasmon and hot carrier properties of metal thin films. Based on the many-body first-principles calculation method, this paper systematically studies the surface plasmon properties of Au(111) films with thickness from monolayer to 5 monolayers, and the energy distribution and transport properties of hot carriers generated by surface plasmons. The study results show that Au(111) filsm have low-loss surface plasmon properties. Meanwhile, the surface plasmons excited at the interface of the Au(111) films and the dielectric are strongly confined, which can enhance the local electric field, thus being crucial in nanophotonics applications. In addition, Au(111) films have high hot carrier generation efficiency, high energy hot electron energy and hot hole energy, and excellent mean free paths and mean free times. Unexpectedly, the direct current of Au(111) films is significantly better than that of bulk Au. These results provide new ideas and theoretical basis for the design and fabrication of Au(111) films in optoelectronic devices and energy conversion devices.