Feasibility of room temperature detection of low energy single ions using nanometer-thick graphite

Abstract

In this work, we demonstrate the feasibility of detecting low energy single ions using nanometer-thick and few-micrometer-wide graphite flakes at room temperature. We used electrically contacted samples of highly oriented pyrolytic graphite and measured in situ the change in electrical resistance upon ion irradiation using a self-made nanovoltmeter. Eight samples of different dimensions were prepared and subjected to ion irradiation from various species. A fluence as low as 5×108cm−2 corresponding to a few hundreds of ions irradiated was sufficient to produce a signal significantly above the noise level. Furthermore, we used a model to describe the dependence of the change in electrical resistance on the defect concentration induced by ion irradiation. By extrapolating this model to the level of single ions, our findings support the feasibility of detecting single ions at room temperature using thin graphite as a detector material.