Electron Hopping Dynamics in Au_(38) Nanoparticle Langmuir Monolayers at the Air/Water Interface

摘要

Gold nanoparticles containing a few tens of atoms have been the focus of recent investigations because of their novel electronic and optical properties.They appear to represent the bulk-to-molecule transition region where electronic band energetics yield to quantum confinement effects and discrete electronic states emerge.The electrochemical and optical properties of these metal quantum dots have been described.A natural extension of these studies is the exploration of the collective properties of assembled arrays of these nanoparticles since practical electronic devices may in fact depend on average properties of their constituents.Although the electron-transfer (ET) dynamics has been extensively studied in three-dimensional network and polyether melt nanoparticle assemblies,the unified picture of the ET dynamics-structure relation remains incomplete.This is largely due to their structural ambiguity and disordering effects.We report here the first quantitative voltammetry at the air/water interface that delineates the distance-dependent electron hopping (self-exchange) dynamics in well-defined Langmuir monolayers of a metal quantum dot.