|
Plasmonic nanostructures have been widely explored to improve absorption efficiency of conventional solar cells, either by employing them as a light scatterer, or as a source of local field enhancement. Unavoidable ohmic loss associated with the plasmonic metal nanostructures in visible spectrum, limits the efficiency improvement of photovoltaic devices by employing this local photon density of states (LDOS) engineering approach. Instead of using plasmonic structures as efficiency improving layer, recently, there has been a growing interest in exploring plasmoinc nanoparticle as the active medium for photovoltaic device. By extracting hot electrons that are created in metallic nanoparticles in a non-radiative Landau decay of surface plasmons, many novel plasmonic photovoltaic devices have been proposed. Moreover, these hot electrons in metal nanoparticles promises high efficiency with a spectral response that is not limited by the band gap of the semiconductors (active material of conventional solar cell). In this work, we will show a novel photovoltaic configuration of plasmonic nanoparticle that acts as an antenna by capturing free space ultrahigh frequency electromagnetic wave and rectify them through an ultrafast hot electron pump and eventually inject DC current in the contact of the device. We will introduce a bottom-up quantum mechanical approach model to explain fundamental physical processes involved in this hot electron pump rectifying antenna and it’s ultrafast dynamics. Our model is based on non-equilibrium Green’s function formalism, a robust theoretical framework to investigate transport and design nanoscale electronic devices. We will demonstrate some fundamental limitations that go the very foundations of quantum mechanics.
|
