Optical Absorption of Proton Irradiated Colloidal CdSe/ZnS Core/Shell Nanocrystals

The excitonic transition observed in the optical absorption spectra of CdSe/ZnS core/shell nanocrystals is investigated as a function of 2 MeV proton irradiation dose. Samples of three different nanocrystal diameters were prepared by embedding the nanocrystals into a UV curable resin. The integrated area of the exciton peak is obtained after irradiating the samples with several irradiation fluences ranging between 1.0×10
¹³
cm
^-2
to 9.5×10
¹⁵
cm
^-2
. The results indicate that nanocrystals with larger diameter (~4.40 nm) are more irradiation tolerant while the excitonic transition is completely degraded in nanocrystals with diameter of ~2.10 nm.