Synthesis of CdTe quantum dots of different sizes and their interactions with water soluble porphyrins

Abstract

Progress in the synthesis of CdTe quantum dots through controlled colloidal-thermal processing and understanding of the factors that control the luminescence quantum yields of CdTe quantum dots enable us to discover technological applications such as fluorescence probes for chemo sensor development and biological imaging, tunable absorbers and emitters in nanoscale electronics, quantum dot lasers and advanced materials for electrochemical applications. In the present study, CdTe quantum dots of different sizes are synthesized in aqueous solution using both anionic (thioglycolic acid) and cationic (2-amino ethanethiol hydrochloride) as stabilizers. The quantum dots are synthesized in a known pH range and the quantum dots are seen to depend on specific pH values depending on the stabilizer added. Their characterization is made using various spectroscopic techniques. The size of the quantum dots is found to vary with the processing time and temperature. Additionally, interaction of the quantum dots with water soluble porphyrins is investigated using steady-state and time-resolved emission studies. Preliminary results suggest photo induced energy transfer as a mechanism of fluorescence quenching.