Vol. 7, Issue 3 (2018)

Author(s):
Deepika and Rakesh Dhar

Abstract:
Herein, we report the synthesis of CdSe Quantum dots of tunable particle size in aqueous phase using freezing temperature injection technique. As prepared CdSe quantum dots were characterized using UV-Vis Absorption Spectroscopy, Photoluminescence Spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy. By varying the concentration of cadmium and selenium precursors with thioglycolic acid as the capping ligand, this synthesis method allow us to synthesize Quantum Dots of size ranging from 3.4 to 3.7nm (estimated from optical absorption edge measurements). Absorption spectra of CdSe QDs exhibit a blue shift as compared to its bulk counterpart which is an indication of quantum confinement effect. The photoluminescence (PL) spectra of CdSe quantum dots confirm that the particles are mono-dispersed and possess enhanced luminescent property. Band gap of CdSe quantum dots was found to be decreases with increase in particle size.