Simulations were conducted to examine hot electron production induced by rastering across the AuNR surface along either the transverse (θ = 90°) or longitudinal (θ = 0°) direction. As shown in Figure , intense plasmonic hotspots occur along the AuNR sides when scanning across the transverse direction (i.e. θ = 90°), whereas scanning longitudinally across the AuNR (i.e. θ = 0°) produces weaker albeit more uniform surface hot electron generation (Figure ). Additionally, due to the AuNR shape anisotropy, the STEM beam will scan ~3 times as many lines over the surface when the nanorod is oriented upright compared to horizontal. There is better alignment between the STEM probe rastering direction and the nanorod transverse axis for upright AuNRs, which promotes intense hot electron generation hotspots along the nanorod sides with each raster pass. Enhancement of side-preferential hot electron generation and silver deposition by this process is consistent with the increasing rate of aspect ratio decrease as θ increases (Figure ).