Going Green with Nanophotonics: Plasmons are optically induced collective electronic excitations tightly confined to the surface of a metal, with silver being the metal of choice. The subwavelength confinement offers the opportunity to shrink optoelectronic circuits to the nanometer scale. However, scattering processes within the metal lead to losses. Lu et al. (p. 450 ) developed a process to produce atomically smooth layers of silver, epitaxially grown on silicon substrates. A cavity in the silver layer is capped with a SiO insulating layer and an AlGaN nanorod was used to produce a low-threshold emission at green wavelengths.

Metal sulfide nanomaterials have attracted great attention because of their excellent properties and promising applications in electronic, optical and optoelectronic devices. Well-aligned nanostructure arrays on substrates are highly attractive for their enhanced properties and novel applications. The general solution route and thermal evaporation under controlled conditions have been utilized for oriented growth of various metal sulfide nanostructure arrays and demonstrated their applications in energy conversion and storage. The article provides an overview of recent research and significant advances reported in the literature, covering from synthesis to properties and to applications especially in energy conversion and storage, such as lithium-ion batteries, solar cells, fuel cells and piezoelectric nanogenerators.