Development of an ionising radiation detector based on quantum dots absorbed in porous glass

In this work, we report measured effects on the fluorescent emission spectra of commercially produced core-shell (CdSe/ZnS) quantum dots (QDs). 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. Recent work on the production of a prototype 2D imaging dosimeter, by absorbing a solution of green emitting QD in toluene into a sample of porous “Vycor” glass, has shown that QDs absorbed in the Vycor fluoresce under several hours of continual illumination and that the system continues to show fluorescence for several days after the initial preparation. Initial results of experiments to dynamically image the Vycor during electron irradiation are presented as is progress on the development of a second prototype device for 2D radiation dosimetry.