Photoluminescence quenching of conjugated polymer nanocomposites for gamma ray detection

The high atomic number of bismuth iodide and the high-sensitivity photoluminescence quenching of conjugated polymers are leveraged in their nanocomposites for the detection of high-energy photons. With the introduction of oleylamine, the composites can be processed from solutions in organic solvent into high-quality films containing as much as 50 wt% BiI₃. BiI ₃ in the resulting ternary composites is dispersed on a nanoscale or smaller, allowing the formation of transparent composites. Oleylamine was found to form an interfacial layer between the polymer matrix and BiI₃ nanodomains to block charge transfer between BiI₃ and the polymer. Upon gamma ray exposure, the luminescent intensity of the ternary composites decreased linearly with the radiation dosage.