Synthesis of CdTe Nanocrystals through Program Process of Microwave Irradiation

Abstract

A novel method, the program process of microwave irradiation (PPMI), which commendably integrates good qualities of microwave irradiation and a programmed heating process, is presented to synthesize high-quality CdTe nanocrystals in aqueous solution. Microwave irradiation, which acts as the heating mode of PPMI, is highly favorable for a narrow size distribution and low concentration of surface defects of nanocrystals. On the other hand, two correlative processes (the first process and the second process) are utilized in PPMI to actualize the programmed heating process, which is an effective strategy to improve the quality of nanocrystals. Thus, a series (diameters approximately 2-4 nm) of highly luminescent (PLQY approximately 30-68%) CdTe nanocrystals were rapidly prepared (reaction time approximately 1-30 min) in aqueous phase through PPMI.

Synthesis and characterization of CdTe quantum dots by one-step method

“…Herein, a proper Cd/Te molar ratio is important for preparation of high quality CdTe QDs, in our experiment, the optimal ratio is 1:0.07. As previously demonstrated, the occupation of surface sites by stabilizer molecules instead of Te atoms has a tremendous contribution in removing the dangling bonds and preventing the oxidation of Te atoms, which is greatly favorable for the formation of high-quality QDs [24]. Therefore, the thiol plays an important role in the synthesis of thiol-capped CdTe QDs, and in most of the "traditional" aqueous approaches, the stoichiometric ratio of Cd to thiol was often set as 1:2.45 [13,25].…”

CHAPTER 11.5. Nanoparticles and Quantum Dots

“…60,127 In our group, He et al developed a method called ''program process of microwave irradiation'' (PPMI) to synthesize CdTe QDs employing a CEM discover system. 128 The CdTe QDs can be synthesized within 30 min and the PLQY was in the range of 30-68%. Using optimum reaction conditions the as-prepared CdTe QDs with both high PLQY (82%) and low FWHM (27 nm) can be obtained, which represented the best results ever reported in aqueous solution.…”

Enhancement effect of CdTe quantum dots–IgG bioconjugates on chemiluminescence of luminol–H2O2 system

“…For preparation of CdTe QDs via microwave irradiation synthetic method, we adopted the previously reported method [36], with little modification. Briefly, fresh NaHTe solution was added to CdCl 2 solution at pH 11.2 in the presence of MSA in N 2 atmosphere, and the molar ratio of Cd 2 + /MSA/HTe À was fixed at 1:1.5:0.2.…”