M. Seyedsadjadi - Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, ۱۴۷۷۸۹۲۸۵۵ Iran.
F. Asgari - Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, ۱۴۷۷۸۹۲۸۵۵ Iran.
N. Farhadyar - Department of Chemistry, Varamin –Pishva Branch, Islamic Azad University, Varamin, Iran.
N. Molahasani - Department of Chemistry, Tehran Shargh (Qiamdasht) Branch, Islamic Azad University, Tehran, Iran.

In this work, we report, optical properties of Cd۱-xSnxTe quantum dots (x= ۰.۰۵, ۰.۱۰ and ۰.۱۵) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related to the increase of nanocrystals diameter with pass the reaction time. This size dependent phenomenon is concerned to the known “quantum confinement” effect and the highest quantum yield has been achieved under our experimental conditions (using thioglycolic acid (TGA) as a modifier agent) when the processing time reached to ۱۵۰ min.

Semiconductor nanocrystals, Colloidal quantum dots, Quantum yield, Crystalline growth, Quantum confinement