Akademik Veri Yönetim Sistemi
Radiation Physics and Chemistry, cilt.244, 2026 (SCI-Expanded, Scopus)
Graphene, with no bulk volume and a large surface-to-volume ratio, exhibits electrical properties that are highly sensitive to surface interactions. This makes it a promising candidate for next-generation radiation sensors. In this work, we investigate the radiation response of a graphene field-effect transistor (GFET) fabricated on a Si/SiO2 substrate when exposed to different ionizing radiation sources. 60Co was employed as a γ-emitter (1.17 and 1.33 MeV), while 90Sr (0.546 MeV) and 131I (0.971 MeV) were used as β-emitters. Our results show that the device exhibits distinct and reproducible electrical responses depending on the radiation type and energy. Exposure to 60Co induced a small, reversible ∼1% increase in current, whereas 90Sr β-particles produced a ∼12% decrease, consistent with surface charge trapping. The strongest effect was observed under 131I irradiation, with current reductions reaching 84–86%, reflecting the combined influence of both β- and γ-emissions. Unlike previous studies that focused on single-radiation exposure, this work provides a direct comparison of γ-, β-, and mixed β/γ sources within the same GFET platform. The findings demonstrate that graphene devices not only detect radiation with high sensitivity but can also differentiate between surface-dominated, bulk-dominated, and mixed interaction mechanisms. This highlights their potential for real-time, isotope-specific dosimetry in medical, nuclear, and space applications.