The significant increasing photoluminescence quantum yield of the CdTe/CdS/ZnS core/multi-shell quantum dots (QDs) by 60Co gamma irradiation

CdTe/CdS/ZnS core/multi-shell quantum dots (QDs) were synthesized by a novel, simple, rapid, one-pot and low-temperature photochemical approach. In this approach, CdS and ZnS shells were grown around CdTe QDs simultaneously. Thioglycolicacid was used as both of the capping agent and sulfur source for synthesis of CdS and ZnS shells around CdTe QDs. CdTe QDs indicated a green photoemission with a PL peak located about 535 nm that after growth of the CdS/ZnS shell red-shifted to about 600 nm. Photoluminescence (PL) quantum yield (QY) was increased significantly from 23% for CdTe to about 55% for CdTe/CdS/ZnS core/multi-shell QDs. In addition to that, for the first time, the effect of the gamma irradiation on the optical properties of CdTe/CdS/ZnS QDs was studied. Synthesized QDs were characterized by means of XRD, EDAX, FESEM, RAMAN, TEM, UV–Vis and PL analysis. The luminescence of CdTe/CdS/ZnS QDs increased dramatically after gamma irradiation and PL QY was reached to about 73%.