TY - JOUR
KW - Mechanical Engineering
KW - Condensed Matter Physics
KW - General Materials Science
KW - General Chemistry
KW - Bioengineering
AU - Fabio Medeghini
AU - Jacob Pettine
AU - Sean Meyer
AU - Catherine Murphy
AU - David Nesbitt
AB - Dielectric coatings offer a versatile means of manipulating hot carrier emission from nanoplasmonic systems for emerging nanocatalysis and photocathode applications, with uniform coatings acting as regulators and nonuniform coatings providing directional photocurrent control. However, the mechanisms for electron emission through dense and mesoporous silica (SiO2) coatings require further examination. Here, we present a systematic investigation of photoemission from single gold nanorods as a function of dense versus mesoporous silica coating thicknesses. Studies with dense coatings on gold nanostructures clarify the short (∼1 nm) attenuation length responsible for severely reduced transmission through the silica conduction band. By contrast, mesoporous silica is much more transmissive, and a simple geometric model quantitatively recapitulates the electron escape probability through nanoscopic porous channels. Finally, photoelectron velocity map imaging (VMI) studies of nanorods with coating defects verify that photoemission occurs preferentially through the thinner regions, illustrating new opportunities for designing photocurrent distributions on the nanoscale.
BT - Nano Letters
DA - 2022-01
DO - 10.1021/acs.nanolett.1c03569
IS - 2
N2 - Dielectric coatings offer a versatile means of manipulating hot carrier emission from nanoplasmonic systems for emerging nanocatalysis and photocathode applications, with uniform coatings acting as regulators and nonuniform coatings providing directional photocurrent control. However, the mechanisms for electron emission through dense and mesoporous silica (SiO2) coatings require further examination. Here, we present a systematic investigation of photoemission from single gold nanorods as a function of dense versus mesoporous silica coating thicknesses. Studies with dense coatings on gold nanostructures clarify the short (∼1 nm) attenuation length responsible for severely reduced transmission through the silica conduction band. By contrast, mesoporous silica is much more transmissive, and a simple geometric model quantitatively recapitulates the electron escape probability through nanoscopic porous channels. Finally, photoelectron velocity map imaging (VMI) studies of nanorods with coating defects verify that photoemission occurs preferentially through the thinner regions, illustrating new opportunities for designing photocurrent distributions on the nanoscale.
PB - American Chemical Society (ACS)
PY - 2022
EP - 644–651
T2 - Nano Letters
TI - Regulating and Directionally Controlling Electron Emission from Gold Nanorods with Silica Coatings
UR - https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.1c03569
VL -  22
SN - 1530-6984, 1530-6992
ER -