Ion track formation via electric-field-enhanced energy deposition

High-energy ion irradiation deposits extreme energy in a narrow range (∼1–10 nm) along ion trajectories in solid through electronic energy loss, producing unique irradiation effects such as ion tracks. However, intrinsic velocity effects impose an upper limit on electronic energy loss that cannot be overcome by adjusting irradiation parameters. We introduce a method using electric fields during irradiation to enhance nanoscale energy deposition by accelerating ion-excited electrons within subpicosecond timescales. Our extended field-enhanced thermal spike model quantitatively describes this enhancement and predicts a significant reduction in the electronic energy loss required for ion track formation in amorphous SiO₂, which is in excellent agreement with experimental observations. This work provides an approach to control energy deposition during irradiation and boosts the wide application of ion tracks in material modification and nanoengineering to much broader extents.