Morphology and Performance of Organic Nanocomposites for γ-Ray Sensing

The interaction of γ-rays with ionic organic composites involves interactions resulting in the photoelectric effect, Compton scattering and pair production. This translates into a better chance of detecting the γ-radiation of a wide range of energies with these composites as compared with traditional inorganic crystalline platforms. The authors synthesized nickel dioxide (NiO2)- and titanium dioxide (TiO2)-doped ethylene carbonate and urea composites for low-energy γ-ray sensing. Nickel dioxide was used as the active species in the matrix, while the effect of the titanium dioxide impurity on the sensitivity was evaluated in the composites. A commercial cesium-137 (Cs-137) radiation source was used to monitor the γ-radiation sensitivity of each composite. The effect of this radiation was evaluated using the current–voltage relationship of the samples over the frequency range 100–100 000 Hz. A significant decrease in current (at different bias voltages) as a function of frequency following γ-ray exposure indicates the potential that these ionic organic composites have for fast and efficient sensors for radiation-monitoring applications.