Facile synthesis of CdTe-based quantum dots promoted by mercaptosuccinic acid and hydrazine

Abstract

CdTe-based quantum dots (QDs) with high photoluminescence quantum yields (PL QYs) were synthesized in a short time (less than 45 minutes). Mercaptosuccinic acid (MSA) was employed as a stabilizer and N₂H₄ as a growth promoter to accelerate the growth of CdTe and CdSe_xTe_1−x QDs. Red-emitting CdTe QDs with a PL QY of 25% were obtained and the highest PL QY reached 55%. CdSe_xTe_1−x QDs with emission peak positions of 518 nm to 750 nm were obtained. The rapid growth of QDs depends on the interaction between MSA and Cd²⁺, and N₂H₄ plays a key role in accelerating the growth to a certain level. Thus, the QD particle size can be controlled by manipulating N₂H₄ concentration in solution. A low N₂H₄ concentration seems feasible to obtain high-quality QDs.