عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Thioglycolic acid TGA capped CdTe quantum dots QDs of different sizes 2.7, 3 and 3.4 nm were prepared by aqueous method. Then, the fresh QDs were illuminated ultraviolet light. There by effect of lighting on optical properties of QDs were investigated systematically. It was revealed that emission spectra of QDs took a sharp change after UV illumination. ultraviolet UV light. There by effect of lighting on optical properties of QDs were investigated systematically. The results show that the magnitude of changes in the fluorescence intensity and peak position varies with the particle sizes. The fluorescence peaks maximum intensity of quantum dots with a size of 3.4 nm; 5.2 times increases after 102 h of UV illumination. Whereas QDs with a size of 3 nm, peak maximum intensity considerably increases 31 times after 88 h illumination. In three instances, the fluorescence peak position is shifted toward the lower wavelengths. As size of QDs decreases, the emission peak position shifts more towards lower wavelengths under irradiation is greater. In this paper, the mechanism of these changes of the optical properties of the QDs is studied.