Effect of gamma radiation on potential ionising radiation detectors and dosimeters based on quantum dots

The fluorescent quantum yield of core-shell (CdSe/ZnS) quantum dots (QDs) in hexane has recently been shown to decrease with increasing gamma irradiation dose. Here we report the effects on the fluorescent emission spectra of commercially produced CdSe/ZnS QDs of 2.5 nm, 3.3 nm and 6.3 nm size in toluene, following exposure to 1 MeV gamma irradiation in the range 0.1-110 Gy. We show that damage depends on the size of the QDs and that increasing the concentration of QDs in the toluene decreases the effect. Recovery of fluorescence quantum yield one day after irradiation has been seen, with full recovery noted for the 6.3 nm QDs.