Insight into plasmonic hot-electron transfer and plasmon molecular drive: new dimensions in energy conversion and nanofabrication

Abstract

Localized surface plasmon resonance (LSPR) of plasmonic nanoparticles and nanostructures has attracted wide attention because the nanoparticles exhibit a strong near-field enhancement through interaction with visible light, enabling subwavelength optics and sensing at the single-molecule level. The extremely fast LSPR decays have raised doubts that such nanoparticles have use in photochemistry and energy storage. Recent studies have demonstrated the capability of such plasmonic systems in producing LSPR-induced hot electrons that are useful in energy conversion and storage when combined with electron-accepting semiconductors. Due to the femtosecond timescale, hot-electron transfer is under intense investigation to promote ongoing applications in photovoltaics and photocatalysis. Concurrently, hot-electron decay results in photothermal responses or plasmonic heating. Importantly, this heating has received renewed interest in photothermal manipulation, despite the developments in optical manipulation using optical forces to move and position nanoparticles and molecules guided by plasmonic nanostructures. To realize plasmonic heating-based manipulation, photothermally generated flows, such as thermophoresis, the Marangoni effect and thermal convection, are exploited. Plasmon-enhanced optical tweezers together with plasmon-induced heating show potential as an ultimate bottom-up method for fabricating nanomaterials. We review recent progress in two fascinating areas: solar energy conversion through interfacial electron transfer in gold-semiconductor composite materials and plasmon-induced nanofabrication.

Highly efficient plasmon-mediated electron injection into cerium oxide from embedded silver nanoparticles

“…A large body of research in the literature is dedicated to this mechanism, spawning an entire field of research called hot carrier science. 20,55,56 Indeed, numerous systems have been identified in which this mechanism takes place. The efficiency of this process is intrinsically limited by competition with electron thermalization within the metal leading to a hot Fermi-Dirac energy distribution in which most electrons do not have sufficient energy to overcome the Schottky barrier.…”

Visible-Light Active Titanium Dioxide Nanomaterials with Bactericidal Properties

“…LSPR covers a wide range of solar spectrum, particularly in the visible and near-infrared (NIR) regions [127,128]. After excitation, LSPR decays non-radiatively into hot electrons and holes through Landau damping, generating highly energetic charge carriers that are typically termed 'hot carriers' [129]. This ultrafast relaxation renders the hot carriers capable of rapidly separating and transferring into semiconductors to drive chemical reactions on adsorbed molecules [128][129][130][131].…”

Gas-assisted transformation of gold from fcc to the metastable 4H phase

“…Newly formed 4H phase can also induce Au-layer sliding inside the fcc nanoparticle, which results in fccto-4H transformation of inner part of the fcc nanoparticle. The Au-layer sliding is possibly promoted by three factors, (i) the increased thermal energy from electron beam (the beam heating effect on the temperature rise at varies voltages and dose rates are shown in Supplementary Table 4; the estimation method see Supplementary Method for detail); (ii) the increased flexibility of gold due to CO adsorption; (iii) the possible extra electrons from electron beam or the locally electron-rich environment [32][33][34] . As shown by Supplementary Fig.…”