Towards nanoscale reality in plasmonic hot-carrier generation

ended

Metal nanoparticles absorb and scatter light much more than their physical size would suggest. This is caused by localized surface plasmon resonances formed upon light illumination in the nanoparticle. The plasmon resonances are characterized by collective oscillations of free electrons in the particle, but soon after its formation, typically on a femtosecond timescale, the collective plasmon mode decays via emission or via non-radiative creation of electron-hole pairs. As a result of the latter decay mechanism, high-energy electrons and holes, so-called hot carriers, are left behind. When these plasmon-induced hot carriers escape from the nanoparticle to the environment, or are induced there directly, they can be utilized for multitude of applications, such as photovoltaics, photocatalysis, or photodetection. Similarly to the plasmon resonance, the distribution of plasmon-generated hot carriers is highly dependent on the size, shape, and composition of the nanoparticle. In recent years, atomic-scale effects on plasmon resonances have become increasingly scrutinized theoretically and computationally along with sophisticated experimental techniques. Despite this development, for plasmonic hot-carrier generation the bulk of the present understanding is based on model systems or approximative methods neglecting the underlying atomic structure. The aim of this project is to develop first-principles methods for addressing plasmonic hot-carrier generation by fully accounting for the atomic structure and elemental distribution, and shed light on atomic-scale effects on hot-carrier generation by virtue of the developed methods.