Year: 2026
Type: article
Abstract: Use of liquid films in liquid-phase focused electron beam induced deposition (LP-FEBID) can enable high growth rate and high purity nanostructure synthesis, but the height and aspect ratio of the deposits are limited by the liquid film thickness and by lateral spreading of reactive species. Here, we introduce a backscattered electron droplet-to-deposit (BSE-D2D) process in which a nanoelectrospray delivers metal-ion precursor containing droplets toward a grounded substrate inside a scanning electron microscope (SEM). The droplets are irradiated primarily by backscattered electrons emitted from the substrate during primary electron beam exposure. This irradiation drives radiolysis inside the droplets and reduces metal ions/ion-complexes to metal atoms before the droplets reach the substrate. Repeated delivery of these droplets leads to nanopillar growth in the direction of nanoelectrospray. The effect of electron energy on nanopillar growth was studied using Monte Carlo simulations, reaction-diffusion simulations, and experiments. Lower primary electron beam energies deliver higher backscattered electron dose to the droplets, leading to faster metal reduction and formation of larger metal nanoclusters that aggregate after reaching the substrate. At higher primary electron beam energies, lower dose delivery produces fewer and smaller reduced species, allowing metal atoms and small clusters to reorganize on the growing nanopillar into larger elongated grains. The visual invesitgation of experimentally obtained morphologies follow the proposed trend, showing a transition from nanocluster aggregation at lower energy to on-pillar metal reorganization at higher energy. These results show that BSE-D2D can extend liquid-phase FEBID to high-aspect-ratio metal nanostructures while using electron energy to influence morphology.
Source: Nanoscale Advances
DOI: 10.1039/d6na00760k
Institution: Georgia Institute of Technology
Language: English
Subfield: Surfaces, Coatings and Films
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,962
Awards: G5395324130, G7133591053
OpenAlex ID: W7225376140